By William Hix & Tara Avants
Assistant Criminal District Attorneys in McLennan County
David Grotberg was a 19-year-old sophomore at Baylor University when he was killed while riding his bicycle in Waco. A car struck him on October 6, 2016, and for years, his killer was unknown, leaving David’s family with little hope of justice. But thanks to a determined investigation, thorough trial preparation, an anonymous letter to police, and a little providence, David’s killer was convicted and sentenced to prison in February 2024.
The crash
Franklin Avenue is one of Waco’s well-traveled roads. It cuts a straight line from a nearby suburb called Woodway to downtown Waco. The speed limit varies between 35 mph and 50 mph (though most locals will admit they don’t follow it), and the lighting varies like the speed—in some spots visibility is fine at night, but in other places it is bad. Like many roads in other Texas towns, Franklin Avenue is seemingly always under construction. On October 6, 2016, Franklin’s right lane was closed at the intersection of 32nd Street as the road approaches downtown Waco, and traffic was relatively light.
David and his girlfriend, Kaitlyn Morris, were biking back from a local movie theater on Franklin. As Kaitlyn rode along, she heard a loud noise behind her and turned to see David’s body flying into the air; he had been struck by a speeding vehicle. Kaitlyn stopped her bike and ran as fast as she could to get to David. She immediately saw that he was already dead based on the extent of his head injuries.
Waco Police Department officers were only a few blocks away from the crash when the dispatch came over the radio. When they arrived on scene, officers found Kaitlyn in shock and covered in David’s blood. They spoke with nearby witnesses, but they could only provide a vague description of the vehicle—a white or light-colored SUV—which had fled the scene.
Months later, Waco PD Detective John Clark had to inform the Grotberg family that there were no more leads to follow; the case had gone cold. The Grotbergs feared that they might never know who had killed their son.
The letter
Prosecutors and police officers know well that anonymous tips often amount to nothing. In the criminal justice and law enforcement world, actionable information coming in spontaneously is rare, and hoax phone calls and faulty information are the norm. In the fall of 2018, two years after David Grotberg’s death, Detective Clark was skeptical when he heard that an anonymous letter had arrived at the police department naming a suspect in a fatality crash. The letter said that Tammy Blankenship had killed David on October 6, 2016.
Despite his skepticism, Detective Clark had a lead for the first time in two years. In addition to naming a suspect to investigate, the anonymous letter also provided several other helpful facts. The letter described how, on the evening of the hit-and-run, Blankenship had been drinking wine at a party for Midway ISD administrators, which was held at a home in Woodway. The letter also identified a key witness for the case—a female coworker—who would later testify in Blankenship’s trial.
Armed with this new lead, Detective Clark began to gather information that would either corroborate or disprove the letter’s claims. He and others in the department took four steps that became critical to prosecuting Blankenship:
1) Detective Clark obtained photos from October 2016 that a local auto repair shop had taken of the damage to Blankenship’s vehicle (a silver Hyundai Accent). Blankenship had brought her car in for repair about a month after the hit-and-run. Photos showed that the damage was all on the front passenger side and that the front windshield was caved inward, similar to what you would expect from striking a human body. There was also a thin, vertical indention on the right side of the front bumper akin to a bike tire frame.
2) Detective Clark located Blankenship’s female co-worker, who was named in the letter, and interviewed her about what she remembered from the morning after David was killed. She saw Blankenship, her supervisor at the time, first thing on October 7, 2016, and Blankenship casually mentioned that she had been in a wreck the night before and was not sure what she had hit. Later that morning, Blankenship summoned this co-worker into her office where Blankenship was shaking and saying, “I killed a kid, I killed a kid,” all while looking at a news article about a Baylor student killed in a hit-and-run the night before.
This co-worker also followed Blankenship while she drove her damaged car to the Walmart parking lot in Marlin (about 45 minutes away) and parked it in the back of the lot; she noted that the windshield appeared to be caved inward. She then drove Blankenship back to Waco where Blankenship asked her to drive two routes because Blankenship could not remember how she had gotten home the night before. The first route they traveled was from Woodway, down Franklin Avenue, toward downtown Waco—right past the crime scene. She recalled that Blankenship found a temporary stop sign laying on the ground near downtown Waco and claimed that this is what she had hit the night before.
3) Detective Clark interviewed Blankenship, and she made numerous admissions: She admitted to being at the party with the Midway administrators on October 6, having multiple glasses of wine, and driving home. She admitted to damaging her car on the way home from the party. At first, she told Detective Clark that she hit a stop sign near her apartment in downtown Waco. However, as the interview progressed, she admitted, “I thought I hit a homeless person,” and then claimed she was not sure what she hit to cause the significant damage to her car. She admitted that she waited several weeks after the crash to report the insurance claim and have the vehicle repaired, saying she could not afford the deductible at the time.
4) Detective Clark obtained Blankenship’s phone records which showed the cell towers that her phone pinged off of on October 6 and in the days after the crash. A Waco PD Crime Analyst, Brett Page, used computer software in the Criminal Intelligence Unit to create maps of Blankenship’s cell phone activity. The map revealed that on the night of the crash, Blankenship’s phone pinged off of a cell tower near the Midway Administrator party in Woodway at 9:46 p.m. At 9:50, the phone pinged off a cell tower very near the crime scene. This was significant because the 9-1-1 call reporting the crash came in at 9:53 p.m. Both the 9:46 and 9:50 calls on Blankenship’s phone were incoming calls from the same phone number. Detective Clark traced that number back to one of Blankenship’s male coworkers. The cell phone records from October 7 also corroborated that Blankenship took her car to Marlin the day after the crash and parked it there for about four hours.
Based on the totality of the evidence, Detective Clark applied for an arrest warrant for the felony offense of Failure to Stop and Render Aid in an Accident Involving Death.
Grand jury
Robbie Moody, an assistant U.S. attorney and former McLennan County prosecutor, was originally assigned to this case. He told us, “When the police arrested the defendant, it was clear that Blankenship had committed the crime, but the case was not ready for the courtroom. We needed to use tools like the grand jury process to shore up our understanding of the facts and eliminate as many weaknesses as possible for our case.”
While McLennan County prosecutors were convinced that Blankenship had killed David Grotberg, they still had work to do before the case could be tried. Our office served grand jury subpoenas on the female coworker named in the letter, Blankenship’s three adult daughters, and a male co-worker with whom Blankenship had an affair in 2016; this man was also at the party on October 6.
Prosecutors also used a grand jury subpoena for the insurance records and audio recording of Blankenship’s claim to her car insurance carrier. In the audio recordings, Blankenship acknowledged that she was behind the wheel of her car and was the sole occupant of the vehicle at the time the damage occurred. She again claimed that she hit a stop sign but this time said that the stop sign went over the top of her vehicle. This was different from her previous description in the interview with Detective Clark that the stop sign was laying down in the grass, popped up, and struck her windshield.
Blankenship’s female coworker provided testimony consistent with what she had told Detective Clark during her interview, but taking her testimony before the grand jury memorialized both her own statements and her recollection what the defendant said. Blankenship’s daughters testified that their mother was a heavy drinker and hardly ever went a night without a glass of wine (or three) in hand. Blankenship had told them that she hit a stop sign.
The male coworker corroborated that Blankenship was at the party on October 6 and acknowledged that he tried to call her twice on her way home, but he claimed to not remember why he called her. These were the incoming calls, the second of which caused her phone to ping off of the cell tower near the crime scene.
Filing charges
Prosecutors then needed to decide what charges to present to the grand jury for indictment. We considered a charge of intoxication manslaughter, but the evidence of intoxication was circumstantial at best. There was evidence that Blankenship drank wine at the party and was unsure of which route she took home; however, based on her being known as a heavy drinker, it was unclear how high her alcohol tolerance was. The party’s host described how Blankenship had been loud and was using profanity in front of the superintendent of the school district, but the witness did not know Blankenship well enough to determine if that behavior was out of the ordinary. The party’s host also recalled receiving a text message from Blankenship the morning of October 7 apologizing for her inappropriate behavior and for drinking too much the night before. Ultimately, prosecutors decided that the charge of manslaughter was a better fit because it could encompass various forms of recklessness.
In 2020, the grand jury returned a two-count indictment for Failure to Stop and Render Aid in Accident Involving Death (a second-degree felony) and Manslaughter (also a second-degree felony). The acts of recklessness alleged in the Manslaughter count were by failing to keep a proper lookout, speeding, driving while intoxicated, failing to yield, and/or driving a motor vehicle into and against a bicycle operated by David Grotberg.
During the height of the COVID-19 pandemic, the case sat idle, along with hundreds of others, waiting for courtrooms to re-open. From 2021 to 2024, Blankenship was out on bond, and her case moved along the trial docket in the 54th District Court.
Getting outside help
Knowing this trial would present new obstacles, we sought help from experienced prosecutors both within and outside of our office. Fortunately, legendary former vehicular crimes prosecutor Richard Alpert had recently moved to Waco; he’s now a professor at Baylor Law School. His expertise helped us to strategize and navigate anticipated defenses, such as a claim that the defendant committed a hit-and-run that night but did not hit David Grotberg, or relying on the eyewitness statements that described a vehicle slightly different from Blankenship’s.
Our first assistant, Ryan Calvert, taught us how to “board” a case and prepare for trial using all perspectives, from experts in the field, such as Richard Alpert, to student interns, who often point out questions we have overlooked. Boarding is a part of our trial preparation where we gather a group and discuss the case.[1] We write on a large whiteboard the names of all witnesses, the criminal charges, pertinent dates and times, and the like. The trial prosecutors start by giving a summary of the case to the group, which is great practice for the prosecutor who will do the opening statement to have a test run. Will Hix, a co-author of this article, planned to use a PowerPoint during his opening statement, so he presented that PowerPoint at the boarding and received feedback from the group about the slides. Based on the feedback, he removed some pictures and changed some wording to improve the presentation.
After the general summary of the case, the boarding group peppers the prosecutors with questions about the facts, evidence, and strategy. The questions helped us know what witnesses may be needed and what follow-up investigation should happen so that we could fill in as many pieces of the puzzle as possible for the jury. We also discussed potential defensive objections and developed areas of caselaw that we needed to research. Lastly, we developed a witness order that allowed for the strongest presentation of the evidence, focusing on primacy and recency (starting strong and ending strong).
We had two separate boarding sessions for this case, about six months apart, to ensure that we allowed time for any follow-up investigation that needed to happen before trial. After the first boarding, we re-interviewed some witnesses to ask additional questions and took more pictures of the vehicle in the impound lot. However, some questions we were never able to answer, such as who wrote the anonymous letter and why Blankenship did not stop despite thinking that she had hit a homeless person.
In the second boarding, Richard Alpert stressed to us what would be our main strategy throughout the trial: to keep the focus on Blankenship. He advised us to concentrate the jury on her admissions, actions, and locations. This meant narrowing our witness lineup and reordering witnesses outside of the standard chronological format.
As with any cold case, the delay made it more difficult to follow up with any forensic investigations. We did not have an eyewitness who observed Blankenship behind the wheel of the car, so we used circumstantial evidence to build the case. The strongest evidence included the damage to the vehicle, Blankenship’s statements in her interview with Detective Clark and to the insurance company, the female co-worker’s testimony, and the maps of her cell phone pings. We knew the evidence pointed to the conclusion that she is the only one who could have been behind the wheel of the car that struck and killed David Grotberg.
The investigation took teamwork from the Waco PD detective, crime analyst, and the prosecutors who secured grand jury testimony and pushed the case onward toward trial. The State was now ready almost eight years after the crime occurred.
The trial
On Monday, January 29, 2024, we began jury selection with a questionnaire, distributed to 100 venirepersons, to address any media issues and to ask personal, intoxication-related questions, including previous life experience with hit-and-run cases. After half a day of individual questioning, 65 jurors entered the courtroom for voir dire. We questioned the panel and many jurors said that they could not be fair and impartial based on prior life experiences involving hit-and-run crimes. As the challenges for cause mounted, we held our breath because we were within just a few jurors of busting the panel. Fortunately, though, enough members were saved that the court empaneled 12 jurors, plus an alternate.
We called Blankenship’s female co-worker during the first day of testimony. She testified that Blankenship, her supervisor at the time, told her that she had been in a wreck the night before and was not sure what she had hit. However, within the hour, Blankenship called this woman into her office and stated shakily, “I killed a kid, I killed a kid,” while staring at a news article that included the words “Baylor student” and “hit and run.” She testified that she did not call the police because she was in shock and did not realize that she needed to report this to law enforcement.
The State moved through its case-in-chief, and we were prepared to call our last few witnesses on Friday. However, a juror called in sick Friday morning and provided a positive COVID test. The remaining jurors were sent home and told to call in if they became ill over the weekend. We were nervous that the other jurors would also test positive and the trial would come to a halt, but we found some hope in that none of the remaining jurors wrote down the court’s phone number when it was read aloud. On Monday morning, the remaining 11 jurors all arrived, and the alternate juror slid into the jury box to fill the vacancy.
We called Detective John Clark to the stand during the second week of trial. On cross-examination, the defense attorney sought to impeach the detective concerning an unrelated internal affairs matter for which Clark had been disciplined more than 20 years earlier. We had been informed mid-trial about this discipline (from a former colleague who’d been following the trial on Twitter) and had told defense counsel immediately. We also objected—strenuously—to the defense’s line of questioning and argued that the law does not permit impeaching the detective by using a specific instance of conduct.[2] Despite our objections, the trial judge nevertheless permitted the defense to question Detective Clark about the 1999 incident. The defense then launched a vicious, personal attack on the officer, which lasted a full day of trial.
While the judge’s ruling frustrated us and we were sensitive to the humiliation that Detective Clark was having to endure, we also sensed an opportunity. We felt we could use the ferocity of the defense’s attack on Detective Clark to highlight how the defense was trying to distract the jury from looking to the defendant’s own actions and statements. We decided to turn the defense’s weapon against them in closing argument. We would hammer home this point: The defense sought to paint the detective as a liar, but they wholly ignored the numerous and blatant lies Blankenship told in her recorded interview. (Our plan to maintain focus on the defendant, as Mr. Alpert had suggested, later proved successful, as the first jury note requested to watch Blankenship’s interview.)
In the middle of the trial’s second week, the defense called Tim Lovett, an experienced expert witness in crash reconstruction. Lovett testified that based on the photos he had reviewed, the damage on Blankenship’s car could not have been caused by striking a bicyclist. He provided the jury with measurements of the bike tire and the height of the bumper of Blankenship’s vehicle, from a front facing picture taken at the impound lot in August 2023. Lovett told the jury that these measurements did not match or fit together.
On cross, Lovett admitted that driving while intoxicated is reckless, which meant that he helped lock in one of our manner and means of committing manslaughter (if the jury believed Blankenship was intoxicated). We also highlighted information that had been presented to the jury but not provided to Lovett prior to his testimony at trial, including the female co-worker’s testimony that she saw the vehicle’s windshield caved in on October 7. Richard Alpert watched Lovett’s testimony and helped us strategize about cross-examination during a short morning break. Following his sage advice regarding Lovett, an expert he had both directed and crossed many times, we narrowly focused our cross-examination to dilute Lovett’s opinions so that the jury might disregard them. We decided to save a photo to present in the second closing argument depicting the side view of Blankenship’s vehicle in the impound lot in August 2023, showing that the front right tire of the vehicle was completely flat—undermining Lovett’s calculations of the height of the bumper. By holding this evidence back during cross, we sought to deprive the defense of an opportunity to explain it away.
The defense also called Blankenship’s landlord, who testified that he saw the vehicle the morning of October 7 and did not notice any significant damage. His testimony contradicted the testimony of the female co-worker and the cell tower data from Blankenship’s phone on October 7. The defendant exercised her right not to testify, and the defense rested its case.
In rebuttal, we called an auto glass repair technician who had been repairing windshields for almost 30 years. We sought to call him as an expert witness, and after a TRE 702 hearing, the court allowed his testimony over the defense’s objection. He testified that he could not say what caused the damage to Blankenship’s vehicle, but it was something heavy, and more importantly, it was not a stop sign that caused the damage. This expert was not a witness the police had ever spoken to, but his important testimony illustrated how prosecutors can strengthen their cases by getting beyond the four corners of the case file.
After deliberating for about six hours, the jury returned a guilty verdict on both the Manslaughter and Failure to Stop and Render Aid counts. On the Manslaughter count, the jury also made a finding that Blankenship used her vehicle as a deadly weapon.
Punishment
In punishment, the defendant was facing two to 20 years in prison on both counts, but she was also eligible for probation. In preparing our punishment case, we subpoenaed an Austin Police Department officer who stopped Blankenship in 2018—two years after David’s death—and found her to be driving intoxicated one evening during a work conference. Even though that DWI case was ultimately dismissed as part of a plea agreement, the officer still provided powerful testimony that Blankenship was again driving intoxicated, even after killing David. Additionally, we presented evidence that Blankenship falsely accused that officer of harassing her in an attempt to escape accountability for her actions. That evidence was critical to show that, despite knowing that she had taken a young man’s life, her behavior had not changed. It also showed that the only thing that mattered to Blankenship was Blankenship.
We also called a Midway ISD administrator who testified that when Blankenship was questioned about the DWI arrest upon returning to school, she lied about drinking alcohol that evening and claimed she was with an administrator from another school district. The school district confronted her about this deception in a subsequent meeting and demoted her as a result.
Finally, we called several members of David Grotberg’s family so the jury would know who David was and what Blankenship had stolen from them.
After we rested in punishment, the defense called two legendary Texas prosecutors to the stand: Kelly Siegler and Lisa Tanner. Both women described Blankenship’s cooperation as a key witness in the David Temple murder prosecution in Harris County, which had been tried first by Siegler in 2007 and retried by Tanner in 2019.[3] Blankenship had been best friends with Temple’s wife, who was eight months pregnant at the time she was killed. Siegler tearfully told jurors that Blankenship would make an excellent candidate for probation, and Tanner testified that Blankenship would likely be able to follow the rules of probation. This was surprising to us and truly a once-in-a-lifetime experience to cross-examine such formidable and famous prosecutors. We pointed out that the jury had far more information about the facts of Blankenship’s criminal actions than the two former prosecutors did.
The jury ultimately rejected probation and sentenced Blankenship to 10 years in prison on both counts.
The lessons
“I get knocked down, but I get up again” seemed to be a theme for the duration of this case, with truth and justice prevailing in the end. This case traveled through three different DA office administrations, the COVID-19 pandemic (with the virus even threatening us during the trial), and various other obstacles. The successful prosecution of this case was the result of the persistence and determination of many prosecutors and staff at the McLennan County Criminal District Attorney’s Office, Detective Clark and others at Waco PD, and the Grotberg family.
Richard Alpert was a tremendous help not only during the trial preparation but also during the trial. His guidance and decades of experience in vehicular crimes helped us to present our strongest case and stay focused despite the trial’s unexpected hurdles.
We also owe gratitude to the author of the anonymous letter. While we have our hunches about who wrote it, the author may remain anonymous forever. Nonetheless, he or she provided the key to unlock the cold case, which is a reminder that justice has no expiration date, that we should never give up hope.
The biggest lesson we will apply to our future prosecutions is a simple one: Know a case’s strengths as well as its weaknesses. Both of us come from competitive athletic backgrounds, so sports metaphors tend to be an easy way for us to communicate ideas to each other. We always need to know what our best play is when it looks like things are going sideways in a trial. What is the pitch that we know the other side cannot hit, and how many creative ways can we come up with to throw it early and often.
In a challenging prosecution, it is easy to panic about a case when a witness—or series of witnesses—do not go as well as you had hoped, as happened with the impeachment of our lead detective. Rather than let negative momentum start to build up against you, stay calm, and always know what your fastball is.
Endnotes
[1] Calvert notes that he learned the tactic of boarding cases from his friend and former boss, Brazos County District Attorney Jarvis Parsons.
[2] See T.R.Evid. 608(b).
[3] Read about the retrial of David Temple at www .fox26houston.com/news/david-temple-trial-sentenced-to-life-in-prison-for-murder-of-pregnant-wife.