ALGER — Law enforcement officials will remain at the scenes of two fatal attacks for a fourth day today, hoping to complete a painstaking investigation into what happened in this secluded area in northern Skagit County.

The violent spree that began in Alger Tuesday and ended with the arrest of Isaac L. Zamora outside the Skagit County Sheriff’s Office in downtown Mount Vernon ultimately left six dead and four injured. Five of the victims, including a Sheriff’s deputy, were killed and two others wounded in the Silver Creek neighborhood.

Police suspect the crimes were committed by Zamora, who lived there and was known as a mentally unstable criminal.

Investigators hope to wrap up the crime-scene investigation in Alger by noon today, said Sgt. Robert Goetz of the Snohomish County Multiple Agency Response Team.

“These are very large crime scenes, and our investigators want to make sure they are very thorough,” he said.

Police released all of the names of the dead Thursday: Deputy Anne Jackson, 40; Chester Rose, 58; David Radcliffe, 57; Greg Gillum, 38; Julie Binschus, 48; and LeRoy Lange, 64.

All of them, except Lange, were transported via motorcade to Everett Thursday afternoon where the Snohomish County Medical Examiner’s Office will perform autopsies over the next three days.

The bodies had remained guarded at the crime scenes since Tuesday while authorities processed the evidence.

An autopsy of Lange, a motorist who was fatally shot on Interstate 5 about two miles south of the Alger interchange, was performed earlier this week in Skagit County, Goetz said.

Police have reported that Lange and Deputy Jackson were shot but have declined to comment on the nature of the attacks on the four others who died.

The four injured are Richard Treston, 61, of Silver Creek Drive; Fred Binschus, 56, husband of Julie Binschus; State Patrol Trooper Troy Giddings; and Ben Mercabo, 37, of Bow.

Although they have a rough timeline of events, investigators still hadn’t collected all the evidence by Thursday and couldn’t provide details of Jackson’s or Zamora’s movements on the afternoon of the slayings.

“We simply are not close to figuring that out yet,” Goetz said. “There is a possibility that we may not know what steps the suspect took and how he went from house to house.”

Police became involved at 2:19 p.m. Tuesday, when two separate 911 calls were made reporting a trespasser. The calls were made by the Rose and Dennise Zamora, the suspect’s mother, Goetz said.

By that evening, authorities had learned that six people were dead and that more were hurt. Isaac Zamora was arrested after a high-speed chase that ended in Mount Vernon.

He remains in the Snohomish County Jail on investigation of six counts of first-degree murder and two counts of attempted first-degree murder in lieu of $5 million bail. The Skagit County Prosecutor’s Office anticipates filing charges today, Goetz said.

In an interview with the Skagit Valley Herald on Thursday, Dennise Zamora remained steadfast in her conviction that the six slain people would be alive if her son could have been incarcerated.

“If he was in his right mind, he would have shot himself. And I wish he had, as hard as it is to have to say.”

Staff writers Marta Murvosh and Gordon Weeks contributed to this story.