Authorities have named 28-year-old Aaron Kyle Huff as the suspect in a gruesome set of six murders in Seattle over the weekend. Police believe Huff shot and killed attendees of a rave afterparty before taking his own life as police closed in on him.

Though no one at the late-night house party that followed the rave knew Huff, he was welcomed early Saturday morning, according to an Associated Press report. Clutching a 12-gauge shotgun and a pistol and wearing bandoliers of extra shells across his chest, the Montana native allegedly opened fire on the crowd, killing four men and two women and seriously injuring two others before taking his own life as police confronted him outside the house. Police said they found an assault rifle, several "banana clips" with 30 bullets each, a machete and several hundred more rounds of ammunition in Huff's car near the scene.

"We're probably the only community in society that would have welcomed somebody so easily," said Travis Webb, a Seattle-area rave promoter who attended Friday night's "Better Off Undead" rave, in which some dancers were made up in dark, tattered clothes and heavy makeup, according to the AP. After the "zombie" rave, which drew about 500 attendees, a number of people migrated to a nearby house party and Huff was invited to come along. The gunman left the house party at some point, returning at approximately 7 a.m. to commit one of the largest mass killings in the city's history, the worst since a 1983 massacre that left 13 dead.

Police do not yet have a motive, but some who knew the 6-foot-5-inch, 280 pound Huff said they were shocked by the crime. "This would have been so far out of character," said Jim Pickett, the assistant manager of the apartment complex where Huff lived with his identical twin brother, Kane. Several others who knew Huff from his home in Whitefish, Montana, told The Seattle Times that he seemed "quiet, polite and nice," though Whitefish authorities described him as a small-town rowdy who was arrested in 2000 for shooting at a public art project with a shotgun while drunk.

Lane Storli was at the afterparty until 5 a.m., but left because he got a "weird" vibe. Storli said there were about 15 people there when he arrived, most sitting around partying to a laptop DJ in a "very mellow, chill" atmosphere. Storli told the Times he left a few hours before the shooting began because, "I felt weird. I was getting bad vibes. It was just a weird party."

When police searched the apartment Huff shared with his brother on Saturday night, they brought out three rifles and what appeared to be a grenade, according to the Times. The brothers, both pizza deliverymen and drummers, moved to Seattle five years ago. Police are still trying to figure out what Huff meant when he wrote the word "now" on a sidewalk and steps near the scene of the crime shortly before the shootings.