The investigation into a Thanksgiving Monday crash in Brampton that claimed the lives of four people has revealed that one of the vehicles may have been engaged in a street race at the time, Peel police say.

The two-car crash happened at around 8:45 p.m. at Bovaird Drive and Gillingham Drive, west of Main Street.

According to Peel police, investigators have determined that 49-year-old Calisto Mendonca was operating a 1998 Pontiac Trans Am “at an extremely high rate of speed” when he abruptly changed lanes, lost control of his vehicle, crossed the median and then slammed into another vehicle driven by 24-year-old Brian McGinnis.

McGinnis, his girlfriend Lauren Bouchard and her sister Michelle Bouchard, all on their way back from Thanksgiving dinner in Georgetown, were pronounced dead on scene, as was Mendonca.

Police say that video recovered from near the site of the crash has since revealed that there was a second vehicle travelling alongside Mendonca’s at a similar rate of speed. Police say that there is evidence indicating that the driver of that vehicle may have been racing Mendonca at the time.

“It is very likely that the other driver involved is aware of this collision,” Staff Sergeant Gary Carty said in a press release. “Our investigators would like to speak with that driver.”

Police have not released a description of the second vehicle but are urging anyone who thinks they may have seen it or Mendonca’s Trans Am on the night in question to come forward.