Broken glass, empty beer cans and a pool of blood mark the spot where an all-night Halloween party ended in violence early Sunday morning, with gunfire erupting outside a west-end industrial bay.

The incident happened around 5:20 a.m. near the King of Rims business on 155th Street and 131st Avenue.

Three people were shot. While their injuries were initially deemed critical, officers say they now believe all victims will recover.

"At this point it's very difficult for our investigators - all the complainants are uncooperative with police," said Staff Sgt. Blair Edl, who added some of the men have had criminal run-ins in the past.

"They're not telling us anything about what had happened so it's making our job a bit more difficult."

Police say they hope to have more suspect information after reviewing security footage provided by a local business.

At this point, they can only confirm they are looking for a group of male assailants.

"It's definitely concerning to police when we have a public gathering… and we have this many shots fired. Our only hope here is that we don't have some innocent person injured as well," said Edl.

"We don't believe this was a random attack at all."

With Files from Sean Amato