GREENVILLE — Authorities late Sunday were still seeking information that might lead them to the shooter who opened fire at a packed party just after midnight Sunday, killing two people and shooting six more before vanishing into the fleeing crowd.

“Out of nowhere just six, seven gunshots just go off boom, boom, boom,” said Markeice Ford, who was at the party. “It just kept going, like it wasn’t going to stop.”

In interviews with WFAA, Ford and other witnesses said when the shooting did stop, partygoers bolted for doors and windows to get out and away from the scene about 2.5 miles outside Greenville.

The light of day revealed a landscape dotted with discarded Halloween masks, paramedic supplies and other leftovers from a revel turned nightmare. Pools of blood could be seen on the ground.

The scene inside the venue was worse, said Sgt. Jeff Haines, a spokesman for the sheriff’s department. “Horrific,” he said of what he witnessed where eight people had been shot, including the two who died.

Four victims remained in critical condition late Sunday.

Though about 750 people were at the party during Texas A&M University-Commerce’s homecoming weekend, few have 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 during a news conference.

Investigators believe a lone male gunman entered the venue through the back door and began firing with a handgun, Meeks said. It appeared the shooter was targeting just one person; others may have been shot at random.

The sheriff described “complete chaos” after the shots rang out, with hundreds of people fleeing, including the gunman. Authorities initially had said 14 people were injured, but later revised that figure.

The 12 injured included six people trampled in the melee or hurt by broken glass as they escaped through windows, Haines said.

The other six were injured by gunfire. Beyond the four in critical condition, one was in good condition, Haines said, and he didn’t know the condition of the sixth.

The two people killed were both males, Meeks said, but he did not know if they were A&M-Commerce students. Neither had been officially identified late Sunday, but family members identified one of the victims to local media as Kevin Berry Jr., 23, of Dallas.

After a vigil for Berry on Sunday night at a Dallas park, at least one person opened fire. Mourners and reporters on hand for the event took cover and at least one vehicle was struck by bullets, according to local media reports. Multiple gunshots can be heard in a video posted by one reporter. There were no immediate reports of injuries.

Earlier, university President and CEO Mark Rudin said via social media that four students who had been at the party were treated and released from area hospitals. He did not identify them.

Rudin added that counseling services were being made available to all students at the university’s counseling center, and a community gathering was set for 4 p.m. today on campus in Commerce.

The party was at a facility called The Party Venue, which is along U.S. 380 outside Greenville. Meeks said he was not aware of any sources of surveillance video in the rural area.

Though the party about 15 miles southwest of campus had been promoted as a homecoming event, it was not officially sanctioned by A&M Commerce. Meeks said most attendees were from late teens into early 20s in age.

The Party Venue is described as an 8,000-square-foot facility with a capacity of 500 — well below the estimated attendance Saturday night.

“The amount of people that were there, the overcrowdedness of it — it gave the opportunity for this shooter to be able to accomplish whatever he wanted to accomplish,” Meeks said. “When you have this many people in one place, it’s an easy target for somebody.”

Word of the violence spread online overnight, with many sharing on social media a graphic video purported to show seriously wounded victims lying on the ground as crying and screaming could be heard in the background.

“I just briefly saw one that was a very graphic video,” Meeks said. “I don’t know that’s going to help anything at all.”

Kimberly Wilson, 46, later Sunday was waiting for a tow truck to get her daughter’s car out of a muddy field nearby. She said her 19-year-old daughter had traveled to the party from Dallas, but ran when she heard gunshots and that she called a sibling to come pick her up.

“She’s angry, hurt, upset. She’s going through that whole emotional thing,” said Wilson, who is retired from the U.S. Army and served in Afghanistan. “When you’ve not been trained to deal with something like that — it just throws you off.”

A Hunt County Sheriff’s patrol sergeant and deputy were at the venue when the shooting happened, Meeks said, having been called there for complaints about illegal parking along the highway outside the packed party. An off-duty Farmersville police officer was also there, working as security for the party.

Sheriff’s officers were at the front of the facility questioning someone who appeared to be intoxicated to the point of incapacitation when they heard gunshots from the back of the building, Meeks said.

He praised the patrol sergeant and deputy, saying the sergeant quickly determined one of the gunshot victims had life-threatening injuries and transported that person to a hospital in his patrol car, while the deputy triaged others until paramedics arrived.

“I believe their actions may have saved lives,” Meeks said.

The FBI and Texas Rangers are helping local officials with the investigation.

Texas A&M University-Commerce was founded in 1889 and was known by several names, including East Texas State University, before joining the Texas A&M system in 1996. With about 6,000 undergraduate students and 4,000 graduate students, it’s the second-largest campus in the A&M system.

— This story includes information from The Associated Press, CBS19 and News-Journal staff.