Seattle, Washington (CNN) -- Investigators searching for the suspected killer of four Seattle-area police officers have rounded up several of his relatives and friends to keep them from helping him escape, a sheriff's spokesman said Monday.





Police have brought in five or six relatives and other acquaintances of Maurice Clemmons, "and we expect that number to grow," Pierce County Sheriff's Department spokesman Ed Troyer said.





Some of Clemmons' family and friends have been trying to help him elude police and seek treatment for a gunshot wound, and they have tried to divert investigators by calling in false leads, he said.





"What we're going to do is eliminate those people, so he'll have no place to go," Troyer told CNN. A raid in the southern Seattle suburb of Renton late Monday was aimed at cutting off Clemmons from that support network, he said.





Clemmons, 37, is an ex-convict with a long rap sheet in Washington and Arkansas, according to authorities and documents. He is wanted in what police called the ambush-style killing of four police officers from Lakewood, near Tacoma, about 40 miles south of Seattle. Witnesses say Clemmons was shot in the torso during the Sunday morning attack, and blood and gauze bandages were found in a truck linked to Clemmons, Troyer said.





The sheriff's department said associates who refuse to cooperate with the investigation could face criminal charges.





Clemmons is thought to have slipped away from a home in Seattle's Leschi neighborhood Sunday night, before police surrounded the residence for about 12 hours. He was not found in the home when the investigators moved in Monday morning, Seattle police spokesman Jeff Kappel told reporters.





His escape was "an unlucky thing for us, and a lucky thing for him," Troyer said Monday night. "But his luck's going to run out, because he doesn't have people to help him do that any more."





The slain officers, three men and a woman, were killed at a coffee shop in Parkland, a suburb of Tacoma. Early Monday, authorities started identifying Clemmons as a suspect, rather than as someone wanted for questioning.





The night before the shootings, Clemmons had threatened to kill police officers, but witnesses did not report those threats until after the slayings, Troyer said on ABC's "Good Morning America."





Clemmons was accused of child rape and assaulting a police officer in May. He had been released on $150,000 bond five days before the shootings, according to court records.





After his arrest, Clemmons' sister told police that he "had not been himself lately" and that his behavior was "unpredictable and erratic."





"He had said that the Secret Service was coming to get him because he had written a letter to the president," an affidavit quoted her as telling investigators.





In addition, neighbors had complained that he had been throwing rocks through their windows. Clemmons' wife told deputies that she and her husband had argued over a "newly discovered child," and she suggested that was why he went on his rock-throwing spree, according to an arrest affidavit.





In 2000, then-Arkansas Gov. Mike Huckabee commuted a 95-year prison sentence for Clemmons, according to documents from the Arkansas Department of Community Correction. He returned to prison in 2001 but was paroled in 2004.





"Should he be found 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's office said in a statement Sunday night.





During his 2008 presidential bid, Huckabee was criticized for granting clemency to another inmate, convicted rapist Wayne DuMond, who was later convicted of raping and murdering a woman in Missouri. Huckabee's statement brought a sharp response from Troyer on Monday.





"We're disappointed that Gov. Huckabee came out in the middle of the night without calling anybody here and blamed this on the criminal justice system in the state of Washington," Troyer said. "We're guessing that's probably a spin doctor, not him."
What did the police do? What is Clemmons being sought for? Who's been helping him? Who sought for the shooting? How many officers were killed?
have brought in five or six relatives and other acquaintances of Maurice Clemmons, suspected killer of four Seattle-area police several of his relatives and friends Investigators four
question: What did the police do?, answer: have brought in five or six relatives and other acquaintances of Maurice Clemmons, | question: What is Clemmons being sought for?, answer: suspected killer of four Seattle-area police | question: Who's been helping him?, answer: several of his relatives and friends | question: Who sought for the shooting?, answer: Investigators | question: How many officers were killed?, answer: four