Who killed two hikers near Mt. Pilchuck?

Two women found slain on a Snohomish County trail have been identified as a Seattle Public Schools librarian and her daughter.

Their cause of death and the official release of their identities are expected to be announced this evening, after the Snohomish County Medical Examiner has identified them through fingerprint or dental records and the next-of-kin has been notified. However, a note outside the home of one of the victims identifies them as Mary Cooper, 56, and Susanna Stodden, 27.

Cooper was a librarian at Alternative Elementary No. 2 at Decatur in Seattle.

Outside the school this afternoon a makeshift memorial was set up by students. Meanwhile, Cooper's husband refused to comment pending official release of the victims' identities by the medical examiner's office. The daughter's roommates also declined comment for the same reason.

The note outside Cooper's home read: "In a time of shock and grief, we would like to focus on the tremendous positive legacy left by this extraordinary mother and daughter. As a librarian, teacher, activist, neighbor, friend and mother, Mary touched the lives of countless people."

A source close to the investigation said Wednesday that the two women, whose bodies were found near a trail in the Mount Pilchuck area Tuesday, had been shot.

The pair were last seen alive at about 10 a.m. on a day hike to Pinnacle Lake, about 20 miles east of Granite Falls.

At about 2:30 p.m., another hiker called 911 after he discovered the bodies a couple of miles up the popular trail near the lake.

The Sheriff's Office declined to talk about their cause of death, other than to say the pair died by "homicidal violence."

Sheriff's spokesman Rich Niebusch also didn't say whether detectives had identified a suspect, but he warned people planning to hike in the Pinnacle Lake area to be cautious.

Niebusch called for the public's help in the case, asking people who were hiking in the area Tuesday and might have seen something to call the sheriff's tip line at 425-388-3845.

Wednesday, the Sheriff's Office finished its investigation at the scene and the bodies were removed by the Snohomish County Medical Examiner's office, the Sheriff's Office and search-and-rescue crews.

Cooper's husband was notified Tuesday night, according to sources.

Niebusch declined to say whether the attack was random, but he did say the women were hiking alone.

The Sheriff's Office is stepping up patrols in the area.

Niebusch said detectives likely recovered some evidence from the scene, and today they'll be processing a late-90s purple Dodge Caravan, which was towed from the trailhead Tuesday and is believed to belong to the women.

Neil Bresheare, a member of the Mountaineers hiking group in Everett who uses the trails in that area, said the news is "disconcerting, because it is a family place, it's a place where you will take the kids."

Though part of the trail is heavily wooded, "You would feel pretty comfortable," he said. "Everybody's pretty polite. I've never had any problems whatsoever."

Acting Ranger Phyllis Reed of the Darrington Ranger District said the area near Pinnacle Lake is popular with hikers coming out of Everett and Seattle.

Bresheare said the two-mile trek is one of the closest to an urban center of its kind.

"It's a pretty lake, you know; it's one of the nicest ones this close," he said.

Brian Alexander: 425-745-7845 or balexander@seattletimes.com. Jennifer Sullivan: 206-464- 8294 or jensullivan@seattletimes.com