Officers Mark Dunakin, John Hege, Ervin Romans and Daniel Sakai were remembered for their dedication to their families, friends and a gritty job they loved despite the crummy hours and dangers.

The four were killed by a 26-year-old parolee, who also died in the gunfight Saturday, authorities say.

The officers' caskets were draped in American flags and shepherded to the arena in caravans that passed under a giant U.S. flag held up by two fire truck ladders as they entered the parking lot.

Pallbearers accompanied the caskets inside the venue while bagpipes sounded throughout the space at the beginning of a solemn ceremony packed with law officers from near and far. Mourners also filled the nearby Oakland Coliseum to watch the televised service.

"They were exemplary men and outstanding police officers. They were our brothers," said acting Oakland Police Chief Howard Jordan said at the outset of the service. "They rest in peace, because they were men of peace."

Oakland police chaplain Jayson Landeza read a letter from President Barack Obama and first lady Michelle Obama.

"Our nation is grateful for the men and women who work in law enforcement," the letter said. "Their commitment to their fellow man will never be forgotten."

New York City Police Lt. Tommy Ng, attending the ceremony, said last week's tragedy brought back some memories of Sept. 11. He said he is not surprised from the outpouring of support his colleagues in Oakland have received.

"When one of us is hurt, all of us are hurt," Ng said before the service. "We're all brothers."

Minneapolis Police Sgt. Steve Blackwell and three other officers drove two squad cars from Minnesota to attend Friday's service and pay their respects to the fallen officers, even though they didn't know them.

"It's a national tragedy, so it cuts pretty deep," Blackwell said. "We want to let the people of Oakland see that we care. I hope that this city find strength from this tragedy to move ahead."

Saturday's violent confrontation amounted to the biggest single day, gun-related loss of life for law enforcement since four federal agents died 16 years ago during a raid on the Branch Davidian cult in Waco, Texas.

Losing so many people at the same time would be devastating for any organization, but Oakland's loss is particularly grievous because of the years of service the slain officers had put in and the kind of men they were, people who worked alongside them say.

Sakai, 35, and Romans, 43, were the valedictorians of their police academy classes. Romans was a weapons expert who trained rookies and superiors alike. Hege, 41, was a former high school PE teacher who joined the motorcycle division just two weeks before Saturday's tragedy.

Dunakin, 40, was a former homicide detective who was the lead investigator on a case involving one of Oakland's most violent and notorious killing crews, which randomly murdered five people in late 2002 and early 2003. He was married to a sheriff's deputy who retired after she was taken hostage during a restaurant holdup. Sakai's widow is an officer for the University of California.

Norma Jean Palmer, 55, of Alameda, hugged longtime Oakland police officer John Wilson as he greeted fellow officers from across the country and she entered the arena before the ceremony.

"You keep your head up," Palmer told Wilson, who nodded slowly.

Wilson, 49, who grew up in East Oakland, said this has been the toughest week in his 25-year career.

"It's been hard, but we're getting through it," Wilson said. "The support we have from our colleagues near and far is much appreciated."

Wilson said he knew all four of the officers killed and promised that their memories will live on.

"They made the ultimate sacrifice," Wilson said. "They will never be forgotten."