Texas authorities have no solid information on the gunman who opened fire at a packed college party just after midnight Sunday, killing two people and leaving six others with gunshot wounds before vanishing into the fleeing crowd.

Attendees of the Greenville-area gathering — an unsanctioned, off-campus celebration held during Texas A&M at Commerce’s homecoming weekend — have not been cooperating with investigators, Hunt County Sheriff Randy Meeks said.

“It appalls me that, as many folks that were there, [they] have not been able to give us a better description of this shooter,” he told reporters at a news conference.

Four people remain in critical condition, Sgt. Jeff Haines of the Sheriff’s Office said Saturday evening. Six people were also bruised or cut with broken glass while trying to escape, he said.

The shooting happened about 12:05 a.m. at an event space called the Party Venue, a barnlike structure along a stretch of Highway 380 northeast of Dallas. About 750 teenagers and 20-somethings were crowded inside and around the venue, some of them in Halloween costumes.

When the shots rang out, law enforcement officers were already on the scene: A Hunt County Sheriff’s Office sergeant and deputy had arrived after receiving complaints about cars parked illegally along the shoulder of the highway. They were outside the front of the building, Meeks said, questioning a partygoer who appeared to be intoxicated to the point of incapacitation.

Gunfire erupted in the back of the building, away from the off-duty officer working at the event. Then came pandemonium as hundreds of people tried frantically to escape.

“They were breaking the glass of the windows trying to get out [of] the building,” Meeks said. “My deputies said there was four abreast trying to get out the front door.”

In the chaos, the shooter — believed to be a man — was able to get away.

Two unidentified men were found dead at the scene. Meeks credited law enforcement officers with potentially saving the lives of other shooting victims, noting that one deputy loaded a man with life-threatening injuries into his patrol vehicle and drove him to a hospital while another helped other victims.

The investigation has been somewhat complicated by the Halloween costumes worn by revelers. Authorities initially reported that a rifle was used in the shooting, only to say later that the weapon was a handgun. Rifle rounds found on the floor turned out to be fake — potentially part of a costume.

Meeks said investigators have theorized that the shooter may have been targeting the first of the two men who were killed. But the investigation, which is being assisted by the Texas Rangers and the FBI, is in its early stages and has been hampered by the reluctance of witnesses to come forward. Investigators had spoken with about 20 people who had not given a “good description of the shooter or who they think he may be,” Meeks said.

The sheriff said the public is not believed to be at risk. But he urged people to come forward with information about the gunman.

“We need to get him off the street as soon as possible,” he said. “And we have very, very little to go on right now.”

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