Philadelphia Gunman Nicholas Glenn Was 'Well Known' to Police, 'Hell-Bent' on Hurting Others

— -- A gunman who went on a shooting rampage through the streets of Philadelphia Friday night, killing one person and wounding three others including a police officer, was "hell-bent on hurting lot of people," the city's police commissioner said today.

The suspect, identified by investigators as Nicholas Glenn, was eventually cornered in an alley and fatally shot by police.

During a press briefing Saturday afternoon, Philadelphia Police Commissioner Richard Ross Jr. said Glenn, who police believe was around 25 years old, had "a pretty significant past" and "was well known to the police department." The suspect is believed to have acted alone and there's no indication so far that he had been radicalized.

"He was hell-bent on hurting lot of people," Ross told reporters. "We still aren't absolutely clear as to why."

A "rambling" note was found at the scene of the overnight rampage that police believe was written by the suspect. The letter, which had the word "doom" written on it, expressed hatred toward police and named a probation officer, the commissioner said.

"Clearly, there's some issues that were going on there," Ross told reporters.

The wild chase and shooting spree began around 11:20 p.m. Friday when Sgt. Sylvia Young, a 19-year-police veteran, was ambushed while sitting in her patrol car in west Philadelphia, police said. The gunman fired 18 times at close range at Young, who was struck several times in the arm and protective vest, police said.

Officers hearing the gunshots began pursuing the shooter, who then fired five times into a nearby bar, hitting a security guard in the leg and injuring a woman. The suspect then shot an additional 14 times into a car, hitting a man and woman in the chest.

The woman, who was 25, was pronounced dead early this morning, police said. Her identity has not yet been released.

Two police officers and University of Pennsylvania police Officer Ed Miller chased the suspect into an alley, where they shot and killed him, police said.

Miller was injured but is in stable condition. Young and the three civilians hit by gunfire were also in stable condition and "good spirits," the commissioner said.

"I cannot say enough about the response of the police officers last night. Absolutely remarkable," Ross said. "The restraint that they used is nothing short of miraculous."

Ross said the gunman was carrying at least three magazines and multiple live rounds. A relative of the suspect aided police in finding a location where investigators believe Glenn had been staying most recently. Inside, Ross said, police found more ammunition.

"This was a horrific night," the commissioner said. "He carried out one of the most violent acts in Philadelphia we've seen in a long time."

The Associated Press contributed to this report.