GLASTONBURY, Conn. (WTNH) — An 18-year-old motorcyclist who died in a crash that also killed a 15-year-old girl last September had alcohol and THC in his system, Glastonbury police revealed Thursday.

According to police, Gordon “Mac” Southby, a Glastonbury High School senior, was riding his motorcycle at an “excessive speed” when he collided with an SUV on Hebron Avenue near the Route 2 eastbound on-ramp on Sept. 25, 2022.

Southby and 15-year-old Andra Spencer, who was a passenger in the SUV, both died in the crash. Spencer was a student at Bacon Academy in Colchester.

Glastonbury police, along with Connecticut State Police investigators, determined many factors contributed to the crash, “all of which were attributed to Southby’s operation of the motorcycle.”

“These included Southby having an elevated blood alcohol content, the presence of THC in his system, and the motorcycle traveling at an excessive speed leading up to the collision,” Glastonbury police said.