Nov. 30, 2009 -- Seattle area police began conducting aggressive operations tonight, raiding homes of suspected cop killer Maurice Clemmons' friends and family, hoping to round up people they believe helped Clemmons evade capture.

More than 36 hours after he allegedly walked into a Lakewood, Wash., coffee shop and killed four police officers in what officials described as an assassination, Clemmons was still at large, despite a massive manhunt throughout the Seattle area.

Police said Clemmons was armed, possibly with several guns, and was wounded. Calling him "dangerous," they said, is an understatement.

Earlier this evening, police said they believed that Clemmons was still alive, despite likely having suffered a potentially fatal wound in the shooting Sunday morning, and that his family and friends had helped him get away from the police hunting him.

Pierce County Sheriff's Department spokesman Ed Troyer told ABC News Seattle affiliate KOMO-TV that the raids tonight were being carried out "to collect evidence against him and against those helping him evade us."

"Our ultimate goal is to get him into custody, but a part of that plan going to be to make everybody's life miserable that's helping him. And if they want to go down one by one, that's fine with us," Troyer said. "And our goal by doing this is to take everybody out of the equation that's helping him. That way, he'll have nobody left, and have to fend for himself."

A search of a Seattle house for Clemmons came up empty today, after police locked down a neighborhood for several hours and a SWAT team surrounded a house, believing the suspect was holed up inside. Police fired teargas into the house in an effort to coax or force Clemmons out.

When there was no response, police sent in a robot to determine whether Clemmons was inside. SWAT team members followed shortly after. Police told ABC News that there are indications that Clemmons, who was believed to have been injured in the shooting, had been in the house, but had slipped away.

Even after the 11-hour standoff ended, there was still a massive police presence in Seattle's Leschi neighborhood, with six blocks blocked off and police from several agencies methodically combing area homes and backyards. The area was described as hilly and wooded, providing lots of hiding places.

A nearby elementary school was closed. The University of Washington, located several miles away from the Leschi area, also sent out a text and e-mail alert warning that Clemmons might be in the area.

A warrant has been issued for Clemmons arrest on four counts of murder and the reward for information leading to an arrest has also been bumped up from $100,000 to $125,000.

Clemmons, 37, has a gunshot wound to the abdomen that could be fatal if untreated, police sources told ABC News. That information came from associates of the suspect who helped him overnight and were later picked up by police.

Authorities say Clemmons had no ties to the house he was believed to have been hiding in and that they believe he was dropped off in the neighborhood Sunday evening.

Troyer said Clemmons is their "number one suspect" and the only man authorities are looking at in the shooting deaths of three Lakewood police officers and one sergeant at the Forza Coffee Shop, south of Tacoma.

A police source has told ABC News that they have recovered the murder weapon. Though more than one gun was recovered, they believe he used only one in the attack, a semi-automatic handgun.

Authorities said the attack was a planned ambush.

"We don't believe he was targeting them in particular," Troyer said. "We just believe he was out to kill some police officers execution style."

Police learned after the attack, Troyer added, that Clemmons had bragged to others the night before the shooting that they should watch the news "because he was going to go kill some cops."

Troyer said people who heard Clemmons' alleged warning called in the tip to police after the shooting.

"They are people they were hanging out with the night before," he said. "They didn't believe him and thought he was crazy."

Troyer said police have interviewed the people who heard the threat, but would not release their names or comment on their identities other than to say they were acquaintances of Clemmons.

Washington Police Fault Arkansas for Maurice Clemmons' Release

Troyer said police narrowed in on Clemmons as a suspect Sunday, their suspicions solidified by news that Clemmons was suffering from a gunshot wound.

The Lakewood Police Department is a small force and the deaths represent a loss of 10 percent to 15 percent of the department. The four officers killed were parents to a total of nine children. Their deaths, Troyer said, should never have happened.

In a news release, the sheriff's office said Clemmons has an extensive violent criminal history from Arkansas, including aggravated robbery and theft. Clemmons also recently was arrested and charged in Pierce County in Washington state for third-degree assault on a police officer and second-degree rape of a child.

Clemmons had been released from custody six days ago, bonding out despite an outstanding warrant from Arkansas, where he was pardoned by then Gov. Mike Huckabee nine years ago after serving 11 years of a potential 60-year sentence.

Troyer faulted the state of Arkansas for not acting on the outstanding fugitive warrant for Clemmons after Washington police notified them that he was in custody.

"We know here in Washington we didn't do anything wrong," Troyer said. "We've arrested him multiple times."

In a statement released overnight, Huckabee called the murder of a police officer "the worst of all murders in that it is an assault on every citizen and the laws we live within."

"Should he be found to be responsible for this horrible tragedy, it will be the result of a series of failures in the criminal justice system in both Arkansas and Washington State," Huckabee said, saying that Clemmons met the conditions for commutation and parole at the time. "It appears that he has continued to have a string of criminal and psychotic behavior but was not kept incarcerated by either state."

Marion Humphrey, the Little Rock judge who urged clemency for Clemmons in 2000 told ABC News today that he was horrified and hurt that the man he recommended for leniency would be accused of such a crime.

"I did what I did, and I stand behind what I did. I regret what has happened and I acknowledge responsibility for what I did," Humphrey said. "At the time he appeared to me to be a person who was trying to get his life back together."

Humphrey, also a Presbyterian minister who presided over Clemmons' wedding, said his consideration was based on his belief in mercy and Clemmons' age at the time.

After the attack, Troyer said, an electronic monitoring device put on Clemmons by the bond company was found to have been cut off his ankle.

Officers were Working on Their Computers When They were Shot

Police said the suspect in the shootings walked up to the counter as if to place an order, then pulled a gun out of his coat and began firing. In a last ditch effort to stop the attack, one of the officers was said to have struggled with the shooter, fighting him out the door of the coffee shop, and possibly getting off a few shots at the gunman, until the officer was shot and killed.

Troyer said over the weekend that the officers were working on their laptops, preparing for the start of their shifts when the shooting started.

"There were marked patrol cars outside and they were all in uniform," Troyer said.

The officers were identified as:

• Sgt. Mark Renninger, 39. He had 13 years of law enforcement experience, and is survived by a wife and 3 children.

• Officer Ronald Owen, 37. He had 12 years of law enforcement experience, and is survived for his former wife and a daughter.

• Officer Tina Griswold, 40. She had 14 years of law enforcement experience, and is survived by her husband and two children.

• Officer Greg Richards, 42. He had eight years of law enforcement experience, and is survived by his wife and three children.

Troyer estimated that a couple of hundred officers from the Washington State Patrol and multiple surrounding police agencies in the area were at the crime scene, with some coming on their own time.

Two employees and a few other customers were in the shop during the attack. All were being interviewed by the Pierce County Sheriff's investigators.

"Some are in shock. They are very upset," Troyer said. "They are the ones who are going to put together for us how this happened."

The Forza Coffee Shop, part of a popular local chain, is on a side street near McChord Air Force Base in Tacoma, about 35 miles south of Seattle. The shop is in a small retail center alongside two restaurants, a cigar store and a nail salon.

Brad Carpenter, founder and owner of Forza Coffee, said his staff was OK and being interviewed by police, and that his main concern was for the families of the police officers.

"I'm a retired police officer, so this really hits close to home for me," said Carpenter, of nearby Gig Harbor.

Troyer said the Lakewood officers were two blocks outside their jurisdiction, and the coffee shop was a popular place for officers from surrounding jurisdictions to meet and share information.

ABC News' Megan Clark and The Associated Press contributed to this story.

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