Updated: Dec. 10, 11:34 a.m.

Montgomery County Judge Mark Keough posted a $1,500 cash bond Dec. 9 after receiving a misdemeanor DWI charge related to a September car crash in The Woodlands on Dec. 8.

Joshua Pullen, a Texas Department of Public Safety patrol sergeant, said in an arrest affidavit that Keough was mentally and physically impaired due to zolpidem, which is sold under brand names including Ambien, when he allegedly struck two vehicles while driving Grogans Mill Road on Sept. 10. A blood sample taken from Keough following the crash showed a concentration of 155.5 nanograms per milliliter of zolpidem in his system, Pullen said.

In a statement following the charge, Keough said he was using a legal sleep aid under his doctor's orders, which was "within normal therapeutic levels" in his blood at the time of his crash.

Keough's arraignment before Judge Dennis Watson of the County Court at Law #1 is scheduled for Jan. 5 at 8:30 a.m., according to information from Montgomery County Clerk Mark Turnbull's office.

Original post: Dec. 9, 2:33 p.m.

A Class B misdemeanor charge of driving while intoxicated stemming from a September car crash in The Woodlands was filed against Montgomery County Judge Mark Keough on Dec. 8.

The crash occurred on Grogans Mill Road near Blue Fox Road around 7:30 a.m. Sept. 10, according to a statement made in an arrest warrant affidavit by Joshua Pullen, a Texas Department of Public Safety patrol sergeant who responded to the incident.

In the statement, Pullen said he determined Keough had been driving a Lexus SUV westbound in the right lane of the road before two collisions took place. Keough's vehicle first struck a Mazda MX-6 from behind, Pullen said, then struck a parked Montgomery County Constable Precinct 5 SUV before coming to a stop. Pullen said Keough and Precinct 5 Deputy Lonnie Harrison, who was in the driver's seat of the parked SUV, were injured in the crash and taken to Memorial Hermann The Woodlands Medical Center for evaluation and treatment.

In his affidavit, Pullen said an October lab report from the Southwestern Institute of Forensic Sciences showed a blood sample taken from Keough at Memorial Hermann around one hour after the crash contained zolpidem, amphetamine and fentanyl, the latter of which Pullen said was given to Keough by Montgomery County Hospital District EMS workers following the crash.

Pullen said Justin Schwane, an employee at the forensic sciences institute, identified the zolpidem—which is sold under many brand names, including Ambien—as "concerning in terms of concentration" in Keough's blood and "seemed to be at a level that could cause someone to be falling asleep."

In a video statement released on his Facebook page Dec. 8, Keough acknowledged the DWI charge and said it stemmed from a sleep aid he said was prescribed legally.

"I want to make it abundantly clear to you that there was no alcohol present, there were no illegal substances present at the time of the crash," Keough said in the video. "The allegations are that my legally prescribed and physician-monitored sleep aid was in my system at the time from the night before. According to information that I've received, the sleep aid in my blood was within normal therapeutic levels, and I assure you was taken according to my physician's orders."

Keough's attorney, Conroe-based DWI lawyer Douglas W. Atkinson, also referenced the allegation's link to a prescription drug as well as Keough's work as county judge.

"Judge Keough understands the district attorney must investigate allegations concerning citizens of Montgomery County and he respects the judicial process. We have been informed that the allegations do not involve any alcohol, illegal drug, or narcotic, but rather prescription medication that is within the therapeutic range," Atkinson said in the statement. "Judge Keough has been fighting for Montgomery County citizens since he took office and nonstop during this pandemic. He has and will continue to fight to make sure Montgomery County citizens can go to work, school, church, and gather with friends and family."

While Keough's and Atkinson's statements highlighted Keough's prescription drug use at a therapeutic level, Pullen's affidavit referenced a 2013 article published by The New England Journal of Medicine concerning a study in which zolpidem levels above 50 nanograms per milliliter were cited as a risk of "significant impairment in driving abilities." Pullen said the October lab report showed Keough's Sept. 10 blood sample contained 155.5 nanograms per milliliter of zolpidem.

Based on his investigation, Pullen concluded Keough "did not have his normal mental or physical faculties" while he was driving "dangerously and erratically" Sept. 10 due to the zolpidem, and the crash could have been avoided if not for impairment caused by the drug.

In Keough's video statement, he also referenced his response to the coronavirus pandemic in Montgomery County this year and said he and his legal team will defend the DWI allegation in court.

"I am humbled and I am honored that I have the opportunity to serve, and I appreciate your support and continued prayers. I am confident that a just result in our legal system will be reached at the conclusion of this case," he said.

Keough's office did not offer further comment on the charge Dec. 9.