As the intense hunt for the killer of Officer Chuck Cassidy stretched through a third day yesterday, Police Commissioner Sylvester M. Johnson said he was "very optimistic" that investigators were closing in on a target.

"I'm just very confident we'll have the person in custody," Johnson said, conveying an upbeat tone for the first time since Cassidy was mortally wounded Wednesday.

By nightfall, with exhausted detectives heading home for breaks from their 18-hour shifts, Johnson was less sanguine about quick results: "Things that look promising don't always pan out," he said.

Yesterday was an emotional roller coaster of a day in the massive manhunt for the tattooed suspect who shot Cassidy in the head after the 25-year veteran interrupted an armed robbery at the Dunkin' Donuts at 6620 N. Broad St.

At an interdenominational prayer service in City Hall, Mayor Street said the city was under "psychological, emotional and spiritual" stress. Cassidy was the third officer shot this week.

At a police promotions ceremony at Temple University, the celebration took on a somber tone as officers expressed a desire to get back on the streets to hunt down Cassidy 's killer.

And the West Oak Lane neighborhood where Cassidy was gunned down, the frenzied activities by police the two previous days was replaced by a subdued calm. The only difference from the usual were four TV news vans parked outside the Dunkin' Donuts where the officer was shot.

Cassidy , 54, died Thursday at Albert Einstein Medical Center. Yesterday, his body was carried in a hearse escorted by dozens of police vehicles to a funeral home in Northeast Philadelphia, where he lived with his wife and three children. The motorcade, accompanied by a police helicopter, shut down traffic on I-95.

Investigators have been pursuing numerous leads that poured in throughout the day. Officials yesterday announced that the reward for Cassidy 's killer had increased to $152,000.

Johnson said investigators have conducted an "enormous" number of interviews. Homicide detectives moved into a special command room on the third floor of police headquarters to coordinate the investigation. They were assisted by officers from federal law-enforcement agencies.

Six religious leaders spoke at the City Hall ceremony, which was broadcast on television and on a large screen in Dilworth Plaza to an audience of several hundred.

"One of our charges is to build positive human relations in the city," said the Rev. James S. Allen, chairman of the Commission on Human Relations, which organized the vigil. "We gather here today at a time when it seems that concept has been shattered to some degree. "

"We have a family that needs a lot of prayer," Street said. "We have a police commissioner that needs to be comforted and supported. "

Johnson did not attend the prayer service; he was at a scheduled police promotion ceremony for 178 captains, lieutenants and sergeants at Temple's McGonigle Hall. The mayor left the prayer service early to attend the promotion ceremony.

Cassidy 's slaying added a gloomy note to the ceremony - and emphasized the importance of the officers' new supervisory responsibilities.

"I think it's fair to say that all of you sitting in front of me right now would rather be any place else but here," District Attorney Lynne M. Abraham said to the officers.

"It doesn't matter if you have a year or 25 years, you may lose your life," said newly promoted Lt. John O'Hanlon, 44, a 23-year veteran of the force. "That's what I'm going to stress to my officers. "

Street, speaking to the promotees, pledged every available resource to help "catch and punish the perpetrator of this violence on a member of our family. "

The measured formality of the ceremonies stood in contrast with the determined intensity of the investigation.

U.S. Attorney Patrick L. Meehan, the top federal prosecutor in the region, visited police headquarters to pledge cooperation. "Everybody's committed to finding the guy who did this and holding him accountable," Meehan said.

The FBI Academy in Quantico, Va., is enhancing a surveillance video of Cassidy 's slaying to develop a better image of the killer, described as a heavyset black man with a hitched gait and a spider tattooed on his left hand. Three specialists took measurements of objects inside the Dunkin' Donuts yesterday to help them with the enhancements, FBI spokeswoman Jerri Williams said.

Agents from the U.S. Drug Enforcement Administration and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives have also joined in the investigation.

Cassidy 's slaying also became a campaign issue.

Michael Nutter, the favorite in Tuesday's mayoral election, held a lunchtime get-out-the-vote rally at JFK Plaza during which he implored citizens to stand up to crime, as Cassidy had.

"This is supposed to be the City of Brotherly Love and Sisterly Affection," Nutter said. "We need to start acting like it. "

"He went in that place. He had no chance," Nutter said of Cassidy . "He had no chance. He was doing his job because he cared about this city. He didn't go the other way. When will we show that same courage? "

Contact staff writer Andrew Maykuth at 215-854-2947 or amaykuth@phillynews.com.

Contributing to this article were Inquirer staff writers Marcia Gelbart, Robert Moran, Jeff Shields, Joseph A. Gambardello and Joseph A. Slobodzian.

Reward Posted

A $152,000 reward has been established for information leading to the arrest and conviction of the man who killed Officer Chuck Cassidy . If you have information, call the Homicide Unit at 215-686-3335. You can also call the Citizens Crime Commission of Delaware Valley at 215-546-8477.

Services Set

Funeral arrangements have been made for the Officer Chuck Cassidy .

A viewing will be held Tuesday from 6 to 9 p.m. at John F. Givnish Funeral Home, 10975 Academy Rd., Northeast Philadelphia.

A second viewing will be at 10 a.m. Wednesday at the Cathedral Basilica of SS. Peter and Paul in Center City. A Funeral Mass follows at noon. Burial will be private at Holy Sepulchre Cemetery in Cheltenham.

philly.com

More coverage, including video of yesterday's prayer vigil: http://go.philly.com/shooting