DALLAS (AP) — A Texas man, not his 13-year-old son, was driving the pickup truck that crossed into the oncoming lane and struck a van carrying New Mexico college golfers, killing nine people, and he had methamphetamine in his system, investigators said Thursday.

The National Transportation Safety Board said two days after the March 15 collision that its preliminary findings suggested that the 13-year-old was driving the pickup that struck the van carrying University of the Southwest students and coaches back to New Mexico from a golf tournament. But the NTSB said Thursday that DNA testing confirmed that the father, 38-year-old Henrich Siemens, was driving and that toxicological testing showed the presence of methanphetamine in the Siemens’ blood.

Siemens and his son died in the crash along with six members of the men’s and women’s golf teams and their coach.

The collision happened in Andrews County, which is about 30 miles east of Texas’ border with New Mexico. Although it’s a rural area, the roads there can often be busy with traffic related to agriculture and oil and gas development.