John Frederick Fifield, 21, pleaded guilty to homicide by vehicle while driving under the influence and related offenses, the DA's Office said.
Authorities say Fifield was going 80 mph in a 55 mph zone at the time of the crash on Dec. 19, 2021.
His westbound Jeep Grand Cherokee struck Blieler's southbound SUV at the corner of Hickory Lane and Snowdrift Road, according to investigators.
Bleiler, 47, of Allentown, was pronounced dead at the scene. A female passenger in his car suffered serious injuries including fractures to her spine, face, and ribs, authorities said.
Prosecutors say Fifield's blood tests showed the presence of THC at the time of the crash.
His sentencing is scheduled for July 5.
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