TYLER, Texas — Smith County Precinct 2 Justice of the Peace Andy Dunklin requested a toxicology report for the two victims of a deadly crash Sunday morning involving a pick-up truck and a charter bus on Toll 49.

RELATED: UPDATE: Police identify 2 men killed after pick-up truck collides with charter bus carrying Brook Hill students on Toll 49

The crash killed Jeffrey Dalton Aynesworth and Payton Joseph Raymond, who were in the truck. Five other people, including Brook Hill students traveling on the bus, were injured.

According to Dunklin, the toxicology report, which shows what substances are in a person's body at the time of an incident, is an important element into the Tyler Police Department's investigation. 

The reason why Dunklin ordered toxicology reports for both victims is because investigators are still unsure who was driving the truck. 

"So they decided to request that both occupants be sent for toxicology only, not for autopsy, just to find out what was in their system," Dunklin said. "Obviously it was an unknown at that time."

Brook Hill bus crash
Road blocked off at Brook Hill bus crash

Dunklin says because the bus driver was not killed in the crash, he has no right to request a report from the bus driver. That decision falls to Tyler police. 

Bus Crash
KYTX CBS19 Staff

Results of the toxicology will take about a month. Afterward, Dunklin will deliver them directly to the investigators. 

Those results will help to determine what substance, if any, had an impact on the crash.