The man suspected in the killings, 28-year-old Issac Zamora, is being held in the Snohomish County Jail for investigation of six murders and two attempted murders and was ordered held on $5 million bail.

In a press briefing Wednesday morning, Sgt. Robert Goetz walked through a preliminary timeline put together by detectives, but said investigators still have a lot of work ahead of them to determine exactly what happened.

The initial 911 call came in at 2:19 p.m. when a deputy responded to a disturbance call regarding an unwanted man at a home at 19887 Silver Creek Drive in Alger, and Goetz said the 911 caller gave no indication that the intruder was armed.

Skagit County Sheriff's Deputy Anne Jackson, 40, arrived at that address at 2:50 p.m. and, for an unknown reason, was led to a nearby home at 19342 Bridle Place.

When the deputy later failed to respond to radio calls from sheriff dispatchers, other deputies went to home and found her shot to death. A man was also found shot to death. He has not been identified.

"Skagit County has suffered a terrible tragedy today," Skagit County Chief Deputy Will Reichardt said at a news conference Tuesday night. "Our thoughts and prayers are with the families of all of the victims."

Jackson joined the sheriff's office in 2002 as an animal control officer and became a deputy in 2005.

Tributes to Jackson, flowers, lighted candles, a stuffed bear and a handwritten banner reading "Heroes (at) home in our hearts" were placed outside the sheriff's office. Jackson is the second Skagit County deputy to die in the line of duty.

Three minutes later, deputies learned that a 37-year-old male motorcyclist from Bow, Wash. had been shot in the arm at the Shell station in Alger. He was treated at Skagit County Hospital and released.

Minutes later, a Washington state trooper in the area spotted the suspected gunman's car and chased him south on Interstate 5. Officials said the man was shooting wildly from his vehicle while speeding down the interstate at more than 90 mph.

A bullet grazed the arm of Trooper Troy Giddings while he was trying to position himself in front of the fleeing gunman in an attempt to stop him. The 42-year-old trooper drove himself to United General Hospital where he was treated and released.

An innocent motorist caught in the gunfire was fatally shot near milepost 238. He was later identified by the Skagit County Medical Examiner as 64-year-old Leroy Lange of Methow, Washington.

The chase finally ended near Mount Vernon when the suspected gunman exited the interstate and ended up at a Skagit County Sheriff's station where he was taken into custody about 4:30 p.m.

At 5 p.m., the owner of a home at 19522 Silver Creek Road -- the street to which Deputy Jackson had initially responded -- returned from work and found two male construction workers who had been shot to death. One of the workers was found dead inside his pickup truck.

Meanwhile, at some point during the afternoon, deputies responded to 19812 Silver Creek Drive to find 61-year-old man Alger man who had been stabbed twice. He was sent to a local hospital and released.

Around the same time, a 56-year-old man came to deputies at 19468 Silver Creek Drive to report he and a woman had been shot. The man was taken to a Bellingham hospital, but his condition is not known.

Isaac Zamora is placed into custody in Mount Vernon, Wash. (AP Photo/Skagit Valley Herald, Scott Terrell)

Deputies then found the body of a woman shot to death nearby at 19526 Silver Creek Drive. Family members identified her as 48-year-old Julie Binschus.

Names of the rest of the victims have not been released.

Goetz said it is a complex crime with eight different crime scenes and more than 100 investigators from the state patrol, Skagit County Sheriff's Office, FBI, Snohomish County Sheriff's Office, Everett Police, Mount Vernon Police, and other agencies have converged on the various scenes and cordoned off large areas around the shooting locations.

He says those who live in the area and have been displaced while the investigation continues could be allowed back home later Wednesday afternoon.

Goetz did not speculate on what might have been the motive for the shootings.

Mother: Suspect had history of mental illness

State Department of Corrections officials said Zamora recently served a six-month Skagit County jail sentence for drug possession and was released Aug. 6. He was under community supervision by Corrections officers, spokesman Chad Lewis said.

Lewis said Zamora reported to his community corrections officer as scheduled and passed drug and alcohol tests. He was next scheduled to meet with his corrections officer on Sept. 10.

Zamora's mother said she had tried repeatedly to get help for her son, whom she described as "desperately mentally ill."

"I would have rather that he would have taken it out on me. I would rather that they would have had to exterminate him, than to kill innocent people. I know that sounds extraordinary because he's my dear son, but it wasn't worth all those lives," Dennise Zamora told KOMO News.

"He destroyed the life and family of a lady that came to our rescue," she said. "Our lives will never be the same, just like all the other people, and there's no way for me to reach out to them.

"It was very apparent that he was very disturbed," said neighbor Shirley Wenrick. "The mother has tried for a long time to get them to lock him up and help him.

"I've seen him running out in the field after rabbits and I said 'what are you doing?' And he said 'I'm going to get the rabbits and I'm going to kill them. I'm going to rip the skin right off of them.'"

Dennise said her son has been suffering from post-traumatic stress syndrome ever since the family's home burned down 12 to 14 years ago, and the symptoms have only worsened over the years. She said he had recently begun sleeping in the woods and breaking into a neighbor's home.

"I told the neighbors to call (police). They need to document it in case we could use it to commit him or something," she said.

Late Tuesday, Gov. Chris Gregoire said she is calling for an independent review of Zamora's criminal history and supervision.

"Due to the gravity of the situation, I am calling for an independent, third party review led by Washington Association of Sheriffs and Police Chiefs President Colleen Wilson, and a prosecutor to be appointed by the Washington Association of Prosecuting Attorneys," Gregoire said in a written statement. "I will be directing them to look into how this case was handled and provide an initial report to me within ten days."

Hours after the shootings, a group of residents gathered at the Alger Bar and Grill.

"It's devastating for this town," Steve Thomas said, "The people here are very law enforcement-friendly. It's very somber."

Detectives have set up a tip line and are asking anyone with information about the shootings to call 360-419-3257.