Jonathan Vanderhost, 45, of Lansdowne, was arrested Monday and charged with homicide by vehicle in the death of 18-year-old Dante DeSimone.
Investigators say Vanderhost had marijuana and prescription medication in his system and was unable to safely drive a car.
The accident happened at 9:30 p.m. on January 12th as DeSimone, a friend, Darby High senior Tim Robison, and another teen were standing in the 500 block of West Baltimore Pike.
Delaware County District Attorney Jack Whelan said at a news conference on Monday that Vanderhost's car slammed into a pickup truck, sending the truck off the road.
"Mr. Vanderhorst turned directly in front of that vehicle, causing a severe impact and forcing the pickup onto the sidewalk area, striking two of the three juveniles," said Delaware County D.A. Jack Whelan.
The crash left DeSimone - a freshman a Neumann University - dead and Robison seriously injured.
Investigators say Vanderhorst should not have been behind the wheel.
"The marijuana was of such a significant extent where our expert witness indicated that he was impaired to the ability to safely operate that vehicle," said Whelan.
Vanderhost is set to face a judge in early March.
A day after the fatal accident, family and friends held a vigil for DeSimone.
DeSimone's family reminded the large crowd of something the Clifton Heights would often say: "Live in today like you could die tomorrow."
