The Montgomery County District Attorney's Office said 27-year-old Jabrial Terry had fentanyl, oxycodone, Benzodiazepines and cannabinoids in his system during the May 4 wreck.
Authorities said Stokes, who was nine months pregnant, was the passenger in a Toyota that Terry's Buick struck head-on on Skippack Pike in Whitemarsh.
The 24-year-old was unresponsive and taken to Abington Hospital, where she died after her baby was delivered in an emergency C-section, authorities said. The baby died five days later from injuries sustained in the crash.
The driver of the Toyota was also injured.
Prosecutors believe Terry was eastbound and driving five miles over the limit when he veered into a drainage ditch, overcorrected, and then swerved into the westbound lane.
Investigators said his Buick had no mechanical issues that would have contributed to the crash. His car was not registered, insured, or inspected, and the VIN number and license plate had both been altered, according to the DA's Office.
Police said they found marijuana in his car and "numerous pills hidden in his groin area" at the hospital, including Oxycodone, Xanax, buprenorphine/naxolone>
Terry fled after the crash but was located and arrested by US Marshals on Tuesday, June 25.
He's charged with homicide by vehicle while DUI, aggravated assault by vehicle, accidents involving death or injury while not licensed, and related offenses. His bail was set at $99,000 which he has not posted as of Thursday, June 27.
Terry is due in court for a preliminary hearing on July 10, court records show.
Click here to follow Daily Voice Lower Merion-Narberth and receive free news updates.