SEATTLE - Someone inside an artsy Seattle cafe where a gunman opened fire threw stools at the assailant during a shooting rampage police described as "callous, horrific and cold," a move that allowed others to run to safety.

Ian Lee Stawicki was armed with two .45-caliber handguns and began shooting Wednesday morning at Cafe Racer, killing four people. Police said he fled and later killed a female motorist, taking off with her SUV.

Stawicki later killed himself as police closed in.

Police said more could have been injured or even killed at the cafe were it not for the actions of the man, whom they did not identify. They did not say whether he was a patron or an employee.

"The hero picked up a stool and threw it at the suspect. Hit him. Picked up another stool, as the suspect is shooting and now pointing (a gun) at him and hits him with another stool," Assistant Chief Jim Pugel said.

"During that time, two or possibly three, people made their escape," he said, adding, "He saved three lives."

The slayings further frayed nerves in an already jittery city that has seen 21 homicides so far this year, as many as Seattle had in all of 2011.

"In my almost 30 years in this department, I've never seen anything more callous, horrific and cold," Deputy Chief Nick Metz said at a Thursday news conference after reviewing video footage of the killings.

The gunman's father struggled Thursday to understand how his son could have gone on a shooting rampage and apologized to the victims' families.

"The first thing I can say, and it doesn't go very far at this point, is I'm so sorry," Walter Stawicki said, his voice quivering. "It sounds so trite, that I feel their grief ... I just hope they understand he wasn't a monster out to kill people."

The 21 homicides this year have the city's leaders wondering what, if anything, can be done.

"The city is stunned and seeking to make sense of it," Mayor Mike McGinn said. "I think we have to start by acknowledging the tremendous amount of grief that's out there from the families and friends of the victims."

In just over a month, a young woman was killed in a seemingly random drive-by shooting in a popular nightlife district and a father who was driving with his family was killed by a stray bullet fired during a fight involving people on the street.

While the city still has low murder rates, pressure is growing on the police to curtail the violence at a time when the department is facing accusations of excessive force. Police have told residents to expect more officers on patrol in high-crime areas.

McGinn said the highest priority would be addressing the "epidemic of gun violence that's plaguing the city." He said he'll look at redeploying officers, as well as legislation.

The gunman's family, meanwhile, is struggling with what could have been had they been able to get Stawicki help sooner.

Ian Stawicki, 40, had suffered from mental illness for years and gotten "exponentially" more erratic, his father said, but family members had been unable to get him to seek help.

Walter Stawicki said he was "bitter" that it was so hard to get his son help.

"He wouldn't hear it," he said. "We couldn't get him in, and they wouldn't hold him ... The only way to get an intervention in time is to lie and say they threatened you. Our hands were so tied."

Walter Stawicki recalled a son who liked dogs, kids and plants. He joined the U.S. Army after graduating high school, but the Army honorably discharged him after about a year, he said.

Since then, Ian Stawicki had bounced around serving as a roadie for bands and helping his mother with gardening.

According to the Seattle city attorney's office, police cited Stawicki in 1989 for carrying a concealed knife and, in 2008, a girlfriend who lived with him claimed he had assaulted her and had destroyed her property. She later recanted, and charges were dismissed because she would not cooperate with prosecutors.

Stawicki obtained a concealed weapons permit in 2010 from the Kittitas County Sheriff's Office. The permit shows he owned six firearms.

Other than a couple of traffic tickets and a fistfight with his brother several years ago - charges were dropped - his son had no criminal record, Walter Stawicki said.

"When you knew him and he liked you, he was the best friend you could have. He was an old-fashioned gentleman," he said. "But when he was having bad days, he scared people."

Stawicki also said he knew his son had guns, but he was more concerned that Ian - a "bean pole" at 6-feet, 150 pounds - would get in a physical altercation and lose.

Stawicki last spoke to his son the morning of the shooting. He recalled a cheerful conversation. "I handed the phone to his mother and I said, 'Gee, he sounds in a good mood.'"

The only survivor of the cafe shooting, Leonard Meuse, was upgraded from critical to serious condition at Harborview Medical Center.

A memorial in front of the cafe grew Thursday as people stopped by to drop off flowers, cans of beer and toy instruments. Two of the victims, identified by friends as Drew Keriakedes, 49, and Joe Albanese, 52, were old-time musicians and regulars at the cafe, where they often played or simply held court.

"They were the life of this place," said Janna Silver, who had known them for a few years. "They were very welcoming, and they'd talk to anyone."

The King County medical examiner's office confirmed the identification of Keriakedes and also identified another cafe victim, Kimberly Layfield, 36.

The carjacked woman was identified as Gloria Leonidas, 52. The Seattle Times said she was a married mother of two from suburban Bellevue. The medical examiner's office does not release hometowns.

Formal identification of the other victims, as well as the victims' cause and manner of death, will be released today, the medical examiner's office said.

Associated Press writer Chris Grygiel contributed to this report. Dininny reported from Yakima, Wash.