IT TOOK OFFICER Jason Walters a moment to realize what was going on. Dispatching himself on a routine call on the afternoon of Monday, March 22: A drunken, homeless man harassing people at Hoyt Arboretum had locked himself in a bathroom outside the arboretum office. Officer Walters knocked on the bathroom door twice, but didn't identify himself as an officer. The door opened, and a blood-soaked man holding an X-Acto knife emerged.

"The first thing I thought when I saw him was 'Oh my God, what's, what's wrong with this, what, what's going on?'" Walters told investigators. He radioed for backup, and 10 seconds later, Walters shot the bloody man, Jack Dale Collins, four times.

Police released the interview with Walters and 18 witnesses on Monday, April 5, in a 456-page packet of police reports describing Portland's second police shooting this year. The next day, the police released a photo of the X-Acto knife Collins was carrying, which police had previously described as a "razor knife with a six-inch handle." The bloody silver knife had a one-inch blade.

The reports provide insight into Walters' thinking as he made the quick decision to use lethal force against Collins, a homeless man who had lived on Portland's streets for more than 20 years ["The Life and Death of Jack Dale Collins," Feature, April 1].

After radioing in for cover, Walters started backing up and told Collins, "Drop it, drop it." Walters says Collins locked eyes with him and started walking slowly toward him. Walters was not sure whether there was someone else in the bathroom behind Collins. He was also worried Collins might bolt inside the arboretum office.

Then, according to Walters, Collins said, "No, I'm not going to do that, I won't." Walters drew his gun.

The investigator asked Walters how he had felt at this moment. "I... I was scared; I mean, I was really startled," replied Walters.

Walters also had a Taser, pepper spray, and baton on his belt, but told investigators that once he drew his gun, it would have been too dangerous to use one hand to switch to a different weapon.

Walters was also not certain that the Taser's probes could pierce Collins' jacket. "I remember thinking the jacket looked like a jacket you might sleep out at night in," said Walters. Backing up against a large potted plant, Walters told Collins again to "drop it" and then fired two rounds of two shots. Collins bled to death on the scene.

On Friday, April 2, a grand jury declined to pursue any criminal charges against Walters.