IT WAS STILL WARM and clear, just past 6 p.m., and the Homicide Unit had a fresh case on its hands.

Mark Mitchell, 20, had been shot to death on Newkirk Street in North Philly, making him the city's 129th homicide victim of 2006.

Investigators collected evidence and scoured the block in search of witnesses before they headed back to the unit's cramped, outdated office on the second floor of Police Headquarters.

On May 8 one year ago, as on any typical night, the detectives stayed busy with their new case for hours.

Then came the call — the one that every cop dreads, the one that sucks all the life out of a room and sends chills through everyone.

A police officer had been shot. The usual office banter came to a halt.

Details were sketchy, but it didn't sound good. The officer had been responding to an armed robbery at a bar and been shot shortly before 10:30 p.m.

"The mood just shifted," said Lt. Walt Bell, whose unit, Two Squad, was working when the call came in. "We knew he could die."

Bell and Detective John Harkins kept in continuous motion between Homicide and the communications room on the third floor to check for updates.

The detectives waited in silence. "I just prayed," said Detective Aaron Booker. "That's all you could do."

By then they knew that Officer Gary Skerski was fighting for his life inside an emergency room at Temple University Hospital, just three miles north of Police Headquarters.

Skerski, 46, had volunteered to work overtime for the mayor's Operation Safer Streets program.

He and his partner, Officer William Alexander, had just arrived at a pub in Northwood, a quiet stretch of the Lower Northeast.

As Alexander hovered near the front of the bar, Skerski went around back. Skerski hadn't even pulled out his gun when he was struck in the throat with a single shotgun blast.

At 11:50 p.m., the official word came down: Skerski was gone.

A single, cold-blooded act had suddenly and permanently changed the lives of countless people.

Skerski's children, Robert, 13, and Nicole, 10, became fatherless. His devoted wife, Anne, became a widow at 45.

Today, the first anniversary of Skerski's murder, is a painful reminder for all who knew him that his death left a wound that may never completely heal.

For Bell and his detectives, today reminds them how they were thrust into the center of a case that pained an entire city.

Their job was to hunt down a cop-killer.

A fateful night

Pat's Cafe, on Castor Avenue near Arrott Street, has been a fixture for 20 years, a popular spot for cops, firefighters and neighbors.

Business was slow the night of May 8, 2006. By early evening, one bartender was serving 13 customers, who were playing darts and sitting around chatting over beers.

Outside in the shadows lingered a young man in a dark-blue Yankees cap and a red, white and blue "State Property" fleece jacket.

He asked a man waiting at a bus stop on the corner for a cigarette, then slipped back from plain sight.

At 10 p.m., a young man in a black mask busted through Pat's front door with a sawed-off shotgun in one hand and a handgun in the other.

"This ain't Halloween, motherf------!" he bellowed, as everyone inside froze in terror.

The gunman made a few things perfectly clear: He was a wanted man, he was looking for cash, and he would not hesitate to pull the trigger.

While a bag was passed around the room for patrons to toss in their wallets and purses, the masked man repeatedly shouted, "Keep your hands up!" He shoved his gun into some customers' faces.

A woman who had been in the restroom when the robber burst into the bar stayed there, trembling as she dialed 911. He found her and forced her to join the others.

The thief grabbed money he planned to use to start a drug-dealing business, according to police. No one in the bar put up a fight.

At 10:09, a police cruiser pulled up with Skerski and Alexander inside.

The robber saw Alexander peeking through the bar window. Patrons heard him mutter something about "getting rid of the cop."

He darted to a back door — the same door Gary Skerski was approaching.

Skerski was a highly respected community-relations cop in the 15th District. Almost every day he was out on the street answering neighbors' complaints and helping people start town-watch groups.

He had little experience with heavily armed criminals.

Skerski inched closer to the bar's back door, with probably no idea that the robber was on the other side.

The gunman swung open the door, spotted Skerski and fired once, striking him in the throat, police said. The robber then spun around and fired two errant shots at the front of the bar, in Alexander's direction.

The shooter dashed down Arrott Street, hopped into a stolen SUV and sped off.

Back at the bar, some customers stayed glued to the floor in fear. Others watched in horror as Skerski wobbled and then collapsed on the pavement, his face covered in blood.

Police officers carried Skerski into the back of a cruiser and raced to Temple. But the damage from the close-range shotgun blast was too severe.

Police Commissioner Sylvester Johnson waited with Skerski's family in the hospital. When doctors delivered the news, Johnson watched Skerski's son cry out for his father and pound his fists on a window.

Back at headquarters, "the enormity of [Skerski's death] hit right away," Bell said.

Bell and his detectives tried to stay composed as they flew into action. One supervisor was sent to the bar, another to the hospital. The neighborhood had to be canvassed for suspects.

Dozens of cop cars converged on Pat's Cafe. Bell's phone kept ringing with off-duty detectives anxious to help.

Homicide Lt. Philip Riehl called in from home and volunteered; Bell asked him to head out to the crime scene.

"It was chaotic out there. There were so many marked police cars, a crush of news media and a lot of people out searching the area," Riehl said.

Riehl made his way into Pat's and watched footage of the robbery and shooting from one of the bar's surveillance cameras.

On tape, Riehl saw a tall, thin man handle his weapons with ease. In one frame, he casually rested the sawed-off shotgun on his shoulder while using his handgun to gesture toward the bartender.

"In a case like this, it's important to try not to become emotional or rattled, because you want to make sure you don't miss anything," Riehl said. While Riehl reviewed the video, cops combed Greenwood Cemetery, hoping to find the gunman lurking behind a grave.

Patrol cars and SWAT teams sped from the bar in opposite directions, chasing down anyone who fit any vague description of the shooter.

Two men were arrested for carrying guns. Cops also found a gun-wielding man clad in camouflage in the middle of Roosevelt Boulevard.

But the all-out effort to track down Skerski's killer proved fruitless that night.

The manhunt was just beginning.

Controlled chaos

Detectives worked through the night, combing Northwood for clues. More arrived early the next morning, eager to begin the chase.

Scores of cops lined up in formation outside Pat's Cafe and some scoured the cemetery again. District captains went door-to-door and jotted down residents' names.

Detective Michael Walters and Sgt. William Britt, of the Homicide Unit's Fugitive Squad, started their day at 6 a.m. with the FBI and U.S. Marshals to track down people wanted for parole violations.

"We were grabbing people that were wanted, people who we thought might possibly have information," Walters said. "Unfortunately, they just didn't have information."

Little was known about Skerski's killer. In the surveillance footage, his face was completely covered. Investigators believed that someone must have had a good look at him outside the bar, before he put on the mask.

A sketch was released that day, but except for the Yankees cap, the killer was painted in fairly broad brush strokes — a 25- to 35-year-old black man, 6 feet tall, 150 pounds.

Reward money came together quickly, growing from a few thousand dollars on May 9 to $125,000 two days later.

The Homicide Unit's phone lines were clogged with tipsters eager to help solve the case or collect the reward. In all, police received more than 300 tips.

"We had two drawers full," recalled Detective Joseph McDermott. "Some were really vague, and some you had to put on the back burner. But we believed that we were going to get him. We thought he was in that tip drawer somewhere."

By the end of the first week, a formal task force was established, linking members of Homicide, the Special Investigation Unit, the Fugitive Squad and a handful of other divisions.

The 20-member team pounded the streets in 12-hour shifts that often grew into 16, with members hoping each tip would offer the key.

They sent the surveillance footage to the FBI's training facility in Quantico, Va., for enhancement.

Neighbors desperately wanted to help. "We had guys who usually speed around in tinted, rimmed-up cars stop and wish us luck," McDermott said.

Cops were comforted to have other agencies help, but sadness choked them.

"It was overwhelming," said Chief Inspector Joe Fox, who had been Skerski's boss in the Northeast years earlier. "If you had a few minutes of quiet time, it would start to seep in, and then you'd have to look for something else to do."

Detective Jack Logan, who works in the Northeast Division's Auto Squad Unit, volunteered to join the task force. He knew Skerski from the job.

"I must have watched the surveillance tape 150 times," Logan said. "Gary was really easy to get along with. Never bothered a soul.

"I mean, he was working overtime to earn money for his family. I have a family, and all I could think about was how I could still go home and see my kids, and Gary's kids lost that. They lost their dad."

Championship fight

By day five, some began to openly worry that Skerski's killer had left town.

"We were no further along after five days than we were after the first day," Bell said, recalling that he shared his frustrations one evening with Detective Booker.

"I said, 'We have not one good tip? A cop was killed, there's a $125,000 reward, everybody is giving their all—and we have nothing?'"

Booker told Bell to put the case in perspective. "He said, 'Lieutenant, relax. It's a championship fight. We're only in the fifth round. We're gonna go 15 rounds. We've got a lot of fight left.'"

The long, intense shifts took a toll. Detectives had little time to take a breather, go home or even eat, but they didn't see another way.

Slowly, they began to piece together the puzzle. They discovered that Skerski's killer's jacket was unusual, one of just 400 State Property fleeces made by a New York manufacturer.

Cops promptly acquired one of the limited-edition jackets and displayed it to the news media.

On May 16, a tip led detectives to hospital security guard who had been waiting to catch a SEPTA bus outside Pat's Cafe the night Skerski was killed.

The security guard had been approached by Skerski's killer for a cigarette, Bell said. The guard got a good look at the man's face, as did a young woman who had passed by the bar at the same time.

The new witnesses helped investigators put together a concise sketch.

"We went back to the bar patrons with the jacket and the new composites," Britt said, "and they pretty much all said, 'That's him!'"

By day 8, the killer had a face and a distinguishable jacket. But who was he?

An answer came from a surprising source.

The big break

Around midnight on May 17, a woman came to headquarters and asked to speak to a detective. She said she was related to the man who killed Gary Skerski.

Detective Logan came to the lobby to take her upstairs. The two shared a chilling elevator ride.

"She had this attitude with me, like, 'Why don't you believe me?'" Logan said.

"Then she pulled out a photograph of him. She said, 'This is him! He's wearing the jacket!'"

Logan thought of the new sketch. "I started shaking. I knew it was him," he said.

The cops believed the killer was 23-year-old Solomon Montgomery.

Though grateful for the break, the detectives puzzled over why the woman had come forward.

"She wasn't in it for the money," Logan said. "She never even called the Crime Commission to get a tip number. Maybe she just wanted to do the right thing."

Now the investigation sped up as detectives tried to find anyone who knew Montgomery. They found two of his cousins in a house on Old York Road who told cops that Montgomery had allegedly confessed to Skerski's slaying.

"He mentioned something to them in general terms," said Detective Walters. "He told them he just wanted to do a robbery, but it went bad — it was either him or the cop."

The detectives also learned from law-enforcement officials in California the truth behind Montgomery's barroom boast of being a wanted man.

He had been arrested in Alameda County, Calif., in July 2005 on charges of carrying a loaded gun and receiving stolen property.

When he failed to show up for a court hearing, a bench warrant was issued for his arrest.

U.S. Marshals helped homicide detectives track down a young woman in Philadelphia who is the mother of Montgomery's young child.

The marshals even found cell-phone records indicating that Montgomery called the mother almost immediately after Skerski was shot.

"She put us on the right path," Sgt. Britt said of the mother. "We got her into our office, and I think the reality set in and she thought, 'Why am I covering for him?'"

By late morning on May 18 — 10 days after Skerski was gunned down — investigators had tracked Montgomery to an apartment in East Germantown.

Now they had to plan how to corner him.

Checkmate

Lt. Bell and Sgt. Charlie Coan sent two detectives, Donnie Marano and Howard Peterman, to Ogontz Avenue to do surveillance.

Detectives Walters and Shawn Mellon went out in an unmarked vehicle to meet them.

"Driving down Ogontz, we passed a Chinese store and a guy walked out that I swore was him," Walters said. "I'll never forget. He had on baby-blue sneakers with orange stripes."

Down the block, the four detectives huddled behind their cars, studying family photos of Montgomery. They looked up to see him stroll out of the apartment complex.

He walked by a gray Volvo SUV — the same one police say he stole earlier in the month and may have used as a getaway vehicle.

"He purposely walked past the Volvo, looking back and forth. We started to make a U-turn, and then he jumped into the Volvo quick," Walters said.

"We tried to box him in, but he gunned the engine and actually forced past our car."

A dramatic alleyway foot chase began as Detectives Logan and McDermott arrived.

"We knew how it was going to end," Logan said. "We knew it would be a shoot-out."

A flurry of gunshots rang out. Cops listening over the radio felt jolts of fear.

"I was in [headquarters], standing in the same exact spot I was the last time I ever talked to Gary, and I heard 'Shots fired' on the radio," Chief Fox recalled. "I thought, 'Please, God, no. Don't let one of us get it.'"

No detective was wounded. Montgomery took a slug to the leg and arm, but refused to go down without a fight.

"Even after he was shot, he was trying to reach for two guns — he had one in each back pocket," Charles said. "He was ready to shoot his way out again."

After a few minutes, Montgomery was taken to Albert Einstein Medical Center in serious condition.

The following day, Montgomery was charged with murdering Officer Gary Skerski.

"It was a total team effort, from the Police Commissioner on down to every cop in the street," Bell said. "I know it was 10 days, but it felt like six months. The entire city was holding its breath."

A trial date has not been set.

"I've been on the job for 37 years, and this is the only case I've felt this deeply," said Fox, who will retire at the end of the summer.

"Those detectives put in 20-hour days and gave their all. There was a sense that the city came together, even though it took something like a police officer getting murdered for it to happen," Fox added.

"The case will stick with me forever." *