A Tacoma police tactical team worked with Renton police officers Monday night to confront a reported acquaintance of suspect Maurice Clemmons at a house on Renton Avenue South in Skyway.
Clemmons remained on the loose late Monday.
Pierce County Sheriff's spokesman Ed Troyer said investigators have been locating and rounding up family members and friends of Clemmons who have reportedly been helping the suspect since Sunday morning's shooting. Officers have detained and questioned people in Skyway and in other operations in the Puget Sound area.
Parts of Renton and Skyway were closed while officers approached the house.
Investigators are planning and executing more searches in the area, but will not disclose when and where until they have been completed, Troyer said.
Police in Seattle pursued several tips in the case early Monday.
Throughout the morning, dozens of detectives, crime scene investigators and other officers from police agencies across the region filed in and out of a blue-gray house in Seattle's upscale Leschi neighborhood near Lake Washington.
Working off a tip that Clemmons was inside, SWAT officers had surrounded the house overnight Sunday. Police later entered the home amid explosions and smoke early Monday after several hours, but found it empty.
Several blocks around the home remained cordoned off from public access Monday, as officers continued to process the house for evidence, though police would not disclose exactly what that evidence was. Still illuminated with a string of white Christmas lights, several windows of the home gaped with holes through which police had shot projectiles before storming in.
Neighbors said a relative of Clemmons lived at the home with her husband and several children. Several neighbors described the family as friendly and outgoing, and said they were shocked by the night's police activity.
"It kind of gets you upset that people you know are good people can get caught up in a situation like this," said John Barber, a neighbor who knows the family casually.
Meanwhile Monday, sheriff's deputies and police officers in armored trucks converged with guns drawn on a duplex on Seattle's Beacon Hill shortly before 9 a.m., ordering its occupants out of the home over a loudspeaker.
Neighbors say a middle-age woman in red pajama bottoms came to the door, and soon officers were canvassing the residence.
Asked at the scene if the incident was related to the Lakewood case, a deputy at the scene only responded "that's a good guess."
Dale Frunk said he watched the incident unfold from his girfriend's home across the street.
"The cops were all hiding behind the trucks, with their guns trained on the house," said Frunk, 51. "They didn't actually bust the door down. They called over the loudspeaker, and the woman came out a few minutes later."
Seattle police spokesman Jeff Kappel said police could not comment on the tips they were pursuing.
Earlier in the day, police searched several buildings and checked the campus at the University of Washington, after a transit bus driver reported dropping off a man who resembled Clemmons' description near the campus at about 7 a.m. Campus police issued a warning to students, faculty and staff to be on alert for the suspect.
Police searched Cowen Park near UW this afternoon, reportedly after finding a blood trail, but have since backed off.
Seattle police also searched a Beacon Hill park and a surrounding wooded area with a sprawling homeless encampment known as "The Jungle" on Monday, but reported no details about the search.