KATY, Texas (Covering Katy News) — Harris County prosecutors have charged a Richmond man with manslaughter, alleging he overrode his Tesla's Full Self-Driving system, accelerated to more than twice the residential speed limit and crashed through the front of a Katy home, killing a woman inside.
Michael David Butler, 44, was formally charged July 1 in the 208th District Court with one count of manslaughter in connection with the June 19 death of Martha Avila. Court records show Butler remains in the Harris County Jail on a $150,000 bond and is scheduled to make his first court appearance Monday, July 6.
The criminal complaint, filed by the Harris County District Attorney's Office, provides the first detailed account of investigators' reconstruction of the crash using vehicle data, dashboard camera footage, cellphone records and medical evidence.
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The Tesla crashed into this house in the 21300 block of Rose Hollow Lane in Katy.
Fatal crash claimed life of woman inside home
According to the complaint, Harris County Sheriff's Office investigators responded shortly after 8 p.m. June 19 to a home in the 1900 block of Blooming Park Lane after a blue 2025 Tesla Model 3 crashed through the brick exterior of the residence.
Investigators said Avila, who was inside the home at the time of the crash, suffered fatal injuries and was pronounced dead later that evening at Memorial Hermann Katy Hospital.
Deputies identified Butler as the lone occupant of the Tesla. He was transported to Memorial Hermann Katy Hospital, where investigators described him as awake, alert, coherent and in stable condition with no serious injuries.
According to the complaint, Butler initially told investigators the last thing he remembered before the crash was driving on Highway 6 while using Tesla's Full Self-Driving, or FSD, mode during his DoorDash deliveries.
Hospital and EMS records cited in the complaint state Butler later told paramedics he remembered "changing the music" and looking at the vehicle's navigation screen before saying "the next thing he remembers... was after he crashed." He also told medical personnel he remembered putting the vehicle in self-driving mode and then "passed out."
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Martha Avila
Medical testing found no evidence of a medical emergency
Investigators said Butler's own medical records did not support a medical explanation for the crash.
According to the complaint, Butler denied feeling ill earlier that day, denied experiencing headaches, dizziness or weakness, denied having any history of seizures or blurry vision, and denied any previous syncopal episodes.
The complaint also states hospital testing and clinical evaluations found no evidence Butler suffered a seizure, stroke or heart attack. Investigators further noted that neither alcohol nor common street drugs were found in Butler's blood or urine.
Vehicle data became central to the investigation
After obtaining Butler's consent, investigators seized the Tesla and downloaded information stored on the vehicle's electronic systems, including its airbag control module, commonly known as the "black box." They also obtained dashboard camera footage, data showing steering, braking and accelerator inputs, and information extracted from Butler's cellphone.
The complaint states investigators reviewed both forward-facing and driver-door camera footage recorded immediately before the crash.
According to investigators, Butler had activated Tesla's Full Self-Driving system after completing what appeared to be his final DoorDash delivery before the collision.
The investigator wrote that his review of Tesla's technology showed the automated driving system still requires an attentive driver.
"I also learned, however, that the driver can always choose to override FSD mode in several notable ways," the investigator wrote. "If the driver wants to stay in FSD mode but wants to travel at a higher speed, the driver can override FSD mode's speed by pressing on the accelerator pedal. By pressing on the accelerator pedal, the driver gains control of the vehicle's speed, while the steering, turning, and destination of the vehicle remain controlled by FSD."
The investigator further wrote:
"FSD mode was designed and is programmed to never travel at excessive or dangerous speeds in any location, unless the driver overrides the speed and gains control of the speed by pressing on the accelerator pedal."
Prosecutors say Butler overrode the system
According to the complaint, Butler left what investigators believe was his final DoorDash delivery shortly after 8 p.m. before activating Full Self-Driving again.
The Tesla proceeded through the neighborhood under FSD control until Butler allegedly pressed the accelerator while approaching a stop sign, overriding the system's programmed speed and allowing the vehicle to continue through the intersection.
Seconds later, Butler turned onto Rose Hollow Lane, a residential street that ends in a cul-de-sac where Avila's home is located.
As the Tesla approached a left turn onto Park Brush Lane, investigators said the Full Self-Driving system activated the left turn signal and began steering toward Butler's next DoorDash destination. Prosecutors allege Butler instead overrode the system by pressing the accelerator, causing the Tesla to continue straight into the cul-de-sac rather than complete the programmed turn.
The complaint alleges Butler gradually increased pressure on the accelerator
According to investigators, as the accelerator input increased, the Tesla accelerated while the steering wheel shifted from turning left to pointing straight ahead, sending the vehicle into the cul-de-sac toward the homes at the end of the street. Investigators wrote that Butler then held the accelerator fully depressed — "pedal to the metal" — for about six seconds.
According to vehicle data cited in the complaint, the Tesla accelerated to approximately 73 mph, more than double the residential speed limit, struck the curb in front of Avila's driveway, became airborne and crashed through the front of the home. The dashboard video ended at the moment the vehicle left the ground. Investigators also noted the brake pedal was never applied during the final minute before impact and that post-crash inspections found no evidence of mechanical failure, a stuck accelerator pedal or interference from the vehicle's floor mat.
Cellphone searches cited in charging document
The complaint also alleges digital forensic investigators recovered Google searches from Butler's cellphone showing frustration with Tesla's Full Self-Driving system in the weeks before the crash.
According to the complaint, searches included "Tesla fsd not aggressive enough 2026," "FSD is not aggressive enough for city driving," and "Tesla fsd too timid."
Investigators cited those searches as part of the evidence supporting their conclusion that Butler intentionally overrode the vehicle's programmed speed controls.
Investigators say evidence supports manslaughter charge
Based on the dashboard camera recordings, vehicle data, cellphone evidence, medical records and inspection of the Tesla, investigators concluded Butler recklessly caused Avila's death by overriding the Full Self-Driving system, accelerating to more than twice the speed limit, failing to brake, leaving the roadway and crashing through the residence.
"Based on: (1) the videos of BUTLER and his Tesla before and during the crash, (2) the black box data showing the live activity of the accelerator pedal, steering, and speed before and during the crash, (3) the Google searches demonstrating BUTLER's recent frustration with the 'timid' nature of FSD mode, (4) the absence of any evidence of mechanical failure in the Tesla, and (5) the absence of any medical evidence ... I have reason to believe and do believe that BUTLER recklessly caused the death of Martha Avila," the investigator wrote in the complaint.
Manslaughter is a second-degree felony punishable by two to 20 years in prison upon conviction.