Lawyers for a retired NASA astronaut charged with murder in a fatal car crash that killed two young sisters contend tests reveal there wasn’t any alcohol in his system, court documents show.

Attorneys for former space shuttle commander James Halsell filed a motion including the test results Thursday.

Halsell, 63, is scheduled to go on trial in Tuscaloosa on March 9 nearly four years after a two-vehicle wreck killed 11-year-old Niomi Deona James and 13-year-old Jayla Latrick Parler and injured their father and a woman. A speeding car driven by Halsell rear-ended a vehicle driven by the man on a rural road, police reports said.

Halsell, who flew five space shuttle missions, has pleaded not guilty. The case was delayed in a logjam of other cases that included capital murder trials, a prosecutor has said.

An indictment alleged Halsell was under the influence of alcohol or drugs, and a police compliant showed Halsell told an officer he drank three glasses of wine in a motel room where officers found an empty wine bottle.

But a laboratory test performed by the state showed no alcohol was involved, the defense argued in court papers. Defense attorney Jim Sturdivant has publicly blamed the wreck on Ambien, and the test showed the sleeping medication in his system.

Halsell was arrested on a drunken driving charge in California more than two years before the crash and pleaded guilty, but prosecutors shouldn’t get to tell Alabama jurors about that case, the defense argued, since no alcohol was involved in the deadly wreck.

Jurors might wrongly decide the case on an “emotional basis” if told about the DUI arrest, the defense argued. Prosecutors have not responded to the argument, but a hearing is schedule for later this month.

Halsell lives in Huntsville, and court documents show he told authorities he was driving to Louisiana to pick up his son when the wreck happened.

Halsell retired from NASA in 2006 and went into the private aerospace industry.