The Office of the Chief Medical Examiner has to use DNA testing to confirm the identities of the three people killed on the Maine Turnpike Wednesday night and additional information about the fiery wrong-way crash might not be released until next week, a Maine Department of Public Safety spokesperson said on Friday.

Maine State Police have released no new information about the crash in the Portland area in which the driver and passenger of a car traveling south in the northbound lanes were killed, as was the sole occupant of the car it hit.

State police continue to investigate the crash, which was reported by multiple callers around 9:40 p.m. Wednesday. Police say a Honda Civic was traveling at a high rate of speed when it hit two other vehicles.

The first crash happened near mile 48 in Portland when the Civic hit a pickup truck. The truck sustained minor damage and its driver was not injured.

Minutes later, the Civic crashed into a Toyota Rav4 near mile 45 in South Portland, engulfing both cars in flames. The occupants of both cars died at the scene.

The medical examiner also will use DNA to confirm the identity of the man who died in a tent fire in Sanford on Nov. 25, Department of Public Safety spokesperson Shannon Moss said. The homeless man had been staying in a makeshift tent off of Eagle Drive. The state fire marshal’s office is investigating that fire.

The medical examiner’s office confirmed Friday it is still working on the DNA identification process for both investigations.

The four unidentified deaths are part of a string of recent cases that have taxed state investigators this week.