PHILADELPHIA (AP) — A “rambling” note expressing hatred for police was found after a man opened fire on a Philadelphia police officer then went on a shooting spree, injuring a second officer, killing a woman and wounding three other people before he was shot and killed by police in an alley, authorities said Saturday.

Philadelphia Police Commissioner Richard Ross said police found what he called a “rambling” note at the scene of the Friday overnight rampage that police believe was written by the gunman and that expressed hatred toward law enforcement and named a probation officer.

Ross said police believe only the one gunman was involved in the violent events, which he described as “completely bizarre.”

The wild chase and shootout through the streets of Philadelphia began about 11:20 p.m. Friday when Sgt. Sylvia Young was ambushed while sitting in her patrol car; she was shot a number of times in the arm and protective vest, Ross said.

The gunman fled then shot into a nearby bar, hitting a security guard in the leg; he grabbed a woman and used her as a shield before shooting her in the leg, Ross said. Moments later, as police gave chase, the suspect shot into in a car, killing a woman and critically wounding a man.

Ross said two police officers and University of Pennsylvania police officer Ed Miller chased the man into an alley, where he was shot and killed. Miller was wounded.

Both Miller and Young, a 19-year police veteran, were in stable condition Saturday at Penn Presbyterian Hospital. Young was struck up to eight times. Bullets hit her protective vest and her left arm.

Aside from the officers, the identities of the suspect and others shot in the spree were not immediately released.

Mayor Jim Kenney praised officers and pleaded with them to follow Young’s example and wear their protective vests.

“Thank you for what you do for us every day, and please, please, please, every shift, please wear your vest,” he said. “They will save your life, as we saw tonight.”