The driver behind the wheel of the truck that fatally struck Dixie Chicks founding member Laura Lynch last week is being investigated for potential criminal charges.
Texas Department of Public Safety PIO Sgt. Eliot Torres tells TMZ that because a life was lost, they're working to determine whether the driver was under the influence at the time of the accident.
They confirm the driver had their blood drawn at the hospital for drug and alcohol testing ... and the results will only be released by the hospital once a judge signs off on the subpoena drawn up by investigators.
If the results come back positive for drugs and/or alcohol, investigators will potentially seek charges against the other driver.
The driver could also be charged with other offenses like reckless driving or unsafe lane change after scene analysis and speaking to witnesses -- but it all depends on what the investigation yields.
As we've reported ... an eye witness has already spoken out ... detailing the moment the truck entered Laura's lane while trying to go around 2 other cars and struck her vehicle head-on on Highway 62 outside of El Paso.
His account was consistent with the way law enforcement described the crash ... the aftermath which can be seen in distressing snaps of Laura's heavily mangled car.