SEATTLE -- Search warrant documents released Tuesday revealed new details of the shooting rampage at a Capitol Hill party where Kyle Huff killed six people before turning the gun on himself.

According to the documents, Huff began firing before he entered the house early Saturday morning. One witness said he heard screams and saw Huff entering the house with a shotgun in his hand. Huff held the gun at his hip, firing at the front door, the witness said. Huff had a look of contentment on his face -- "almost a smile" -- as he fired, according to the witness's account.

Other witnesses said Huff walked through the house calmly firing both a shotgun and a handgun at everyone he saw. One witness said Huff shot one male victim near the front door and, after the victim went down, he calmly walked to the man and fired a round at the victim’s head point-blank, according to the documents.

One survivor hiding under a bed saw Huff's feet as he walked into the room and heard him say, "I've got enough ammunition to shoot everybody," according to the documents.

A witness who lived at the house said that he and his roommates did not know Huff but when he and his roommates discussed inviting people over, they decided to invite Huff because he was standing on the sidelines quietly keeping to himself. The witness described Huff as "sketchy" and thought it would be "entertaining" to have such a person at his house. He said after he invited Huff, Huff seemed friendly and agreed to come over.

The documents also described what police officers found at Huff's apartment, which he shared with his twin brother in North Seattle.

According to documents, police took from the apartment six bags of some kind of green vegetable matter, five brochures for Bushmaster rifles, numerous guns, a gun scope and ammunition.

According to documents, police also found an AR-15 rifle, numerous rounds of ammunition and two 5-gallon cans of gas.