The documents seen by the San Antonio Express-News also show Jack Dillon Young told a state trooper he had taken prescription medication before the collision.
The truck the 20 year old was driving collided 75 miles west of San Antonio with a minibus carrying 14 members of First Baptist Church of New Braunfels back from a retreat.
No criminal charges have yet been files after the incident which occurred on 29th March, while a Department of Public Safety investigation is expected to take one month.
A copy of an affidavit obtained from Uvalde County by the Express-News revealed another state trooper reveal he had probable cause to think Young was intoxicated at the time of the incident.
Uvalde County and Real County officials confirmed they received reports of a white pick-up truck driving erratically shortly before the crash.