PENN HILLS, Pa. - A parolee wearing an electronic ankle bracelet fatally shot a man at his home over a $500 drug debt, then walked outside and opened fire on a patrol car, killing a police officer awaiting backup, authorities said.

Penn Hills police Officer Michael Crawshaw, 32, was the first to respond to a 9-1-1 call made about 8:20 p.m. Sunday. Crawshaw was advised to wait in his patrol car because of past problems reported at the home and because dispatchers heard shots over the phone, Penn Hills Chief Howard Burton said.

Ronald Robinson, 32, opened fire with an assault rifle as he approached the car, Allegheny County Police Superintendent Charles Moffatt said yesterday.

"He didn't go rushing in by himself; he wasn't [trying to be] a hero," Burton said of Crawshaw.

Robinson confessed to killing both men and told police he threw two guns into the nearby woods as he ran from the crime scene, according to a criminal complaint obtained at Robinson's arraignment. Police yesterday found a 7.62 mm Norenko MAK 90 assault rifle and a 9mm Ruger handgun in the woods, the complaint said.

The officer's weapon was removed from his holster, showing that he might have been able to draw his pistol and fire a shot, Moffatt said. Police were still investigating.

Robinson fired at least nine shots at the officer, Moffatt said. An autopsy determined that two shots hit Crawshaw in the left arm and a fatal shot hit him in the head, near his left eye, according to the complaint. The man in the house, Danyal Morton, 40, died of several gunshot wounds.

Robinson told police that he shot both men with the assault rifle and that he fired at Crawshaw after the officer saw him come out of the home and told him to stop, the complaint said.

Robinson, of Pittsburgh, was charged with two counts of criminal homicide, four weapons charges, and one count each of burglary and robbery for allegedly bursting into Morton's home and demanding money from him, the complaint said.

Police said Lamar Jay, 25, who lived with Morton, identified Robinson as the gunman. Jay said he heard several gunshots after Robinson went upstairs to confront Morton. After finding Morton dead, Jay went outside and began yelling that someone had been killed in his bathroom, the complaint said.

Robinson agreed to meet police for questioning about 4 a.m. yesterday, Moffatt said. At a video arraignment before a Pittsburgh District Judge yesterday a preliminary hearing was set for Friday and Robinson was held without bond.

Robinson agreed to go to the police station after being contacted by authorities, who tracked him down because he was on parole and wearing an electronic ankle bracelet.

Robinson had been under supervision since 2007 for a firearms conviction, but was due to complete his sentence Feb. 24, said Leo Dunn, a spokesman for the state Board of Probation and Parole Department. Dunn said Robinson, who has an arrest record for drug and firearms charges, did have parole violations, but he was not able to discuss them.

Crawshaw was taken to UPMC Presbyterian Hospital, where he was pronounced dead shortly before 9 p.m.

Morton called 9-1-1 and was found dead in a second-floor bathroom, Moffatt said.

Morton owed Robinson $500 for either cocaine or heroin from a drug deal Saturday, Moffatt said. Both shootings occurred within four minutes, judging by 9-1-1 records and police logs.

The slain officer apparently heard gunfire as he sat in his car awaiting backup officers and was shot moments later, Moffatt said.

Morton has a criminal record dating to 1991, including two prison terms for burglary, records show.

Neighbors reported hearing about 10 gunshots at the home in Penn Hills, a middle-class community about 10 miles east of Pittsburgh.

Robert Cephas, 57, who lives next door, said that he wasn't home at the time but that his wife and grandkids were.

"They were hitting the floor, my grandkids did," he said.

Crawshaw was a three-year member of the force and had worked at the University of Pittsburgh Police Department, Burton said.

William Crawshaw said his nephew was easygoing but wanted more excitement than the university job offered.

"He was interested in a little more - I don't like to use the word action - but that's about all, I guess," he said.

"Officer Crawshaw was a fine officer, and Penn Hills was lucky to have him patrolling our community," Mayor Anthony DeLuca Jr. said.