The officer said when he boarded the bus, he saw Sorrell Groves, 27, of West Philadelphia, in the rear with a gun tucked in his waistband.
When Groves pushed the officer in a bid to get away, Pawlowski grabbed the man by the shirt and pulled the pistol from his waistband, the officer testified at a preliminary hearing.
That's when the struggle began, Pawlowski said.
He said Groves kept grabbing for the gun, so he decided to drop it to the floor to keep it from his reach.
The pair them spilled out the back passenger door of the bus, the gun tumbling down the steps with them to the street, in view of the same Dunkin' Donuts where Officer Chuck Cassidy was fatally wounded in October.
"I felt I was fighting for my life," Pawlowski said under questioning by Assistant District Attorney Patrick Doyle.
The officer said that while the struggle was still underway, the bus driver got off the bus and retrieved the gun from the ground at Pawlowski's direction.
A backup officer helped Pawlowski subdue Groves, who was wearing a bulletproof vest with trauma plate, Pawlowski testified.
The serial numbers had been obliterated from Groves' handgun, said the officer, the only witness to testify at the hearing.
It ended with Municipal Court Judge David C. Shuter ordering Groves, who has an arrest record dating back to 1999, held for trial on aggravated assault and other offenses, including a count of possession of an instrument of crime for the body armor.
Contact staff writer Joseph Gambardello at jgambardello@phillynews.com. 
