Twenty-seven-year-old Upper Darby resident Marvin Marmolejos entered the plea in Delaware County Court on Thursday. He also acknowledged having drugs on him at the time of the parking lot confrontation.
The Upper Darby police officer, Ray Blohm, is recovering, but still has a bullet lodged in his back.
Police say the 31-year-old Blohm ordered Marmolejos to stop, but that the suspect pulled out a pistol and started firing.
The 10-year veteran was hit four times. He fired back, hitting the suspect several times.
Prosecutors say they will seek a sentence of at least 20 years in prison. Sentencing is scheduled for November.
Information from: Delaware County Daily Times