Police block the entrance to the nightclub after the shooting Wednesday night.
Gunman kills four at Ohio rock concert.
Witnesses recount a deadly shooting spree at a nightclub.
Gallery: Nightclub shootings
COLUMBUS, Ohio (CNN) -- A 25-year-old man stormed the stage at a heavy-metal rock concert Wednesday night, shooting and killing Damageplan guitarist "Dimebag" Darrell Abbott and three others before a police officer shot and killed him, Columbus police said.
On Thursday, police identified the suspect as Nathan Gale of nearby Marysville. A spokesman said police had no information about a motive or possible link to the band.
"Right now we don't see any connection at all, but that could change," Columbus police Sgt. Brent Mull said. "Unless he left a note or there's something else, we may never know the motive."
At least two people also were wounded in the attack, which occurred shortly after Damageplan began its performance at the Alrosa Villa nightclub on Columbus' north side.
James Nigameyer of the Columbus police was nearby and responded to a call about the shooting. He slipped in a back door, and someone directed him to the stage, Mull said.
"We got the call about 10:18, and by 10:20 he was in there," Mull said, adding that "it was probably less than a minute before he engaged" the suspect, who was holding a hostage.
"The officer was able to strategically gun this guy down before he was able to kill his hostage," Mull said. "It appeared he was about to kill his hostage before this officer put an end to it."
Mull said the hostage was unharmed and that Nigameyer's action saved lives.
"The officer ran in without any backup ... obviously put himself at risk," he said. "The community has a real hero here."
Abbott, 39, and his brother, Vinnie Paul Abbott, 40, formed Damageplan after the breakup of Pantera -- a group they formed in the 1980s. Their father is Jerry Abbott, a country and western songwriter and producer.
At least one of those killed -- Nathan Bray, 23 -- was a member of the audience. Mull identified another deceased victim as Erin Halk, 29, although it was unclear if he was a concertgoer or an employee.
Mull did not identify the remaining fatality. Abbott was the only band member confirmed dead "at this point," he said.
One of the wounded is in critical condition, the other hospitalized with non-life-threatening injuries, police said. Two others were hurt and treated at the scene, although the nature of their injuries was unclear.
Mull said homicide detectives are checking possible amateur video shot inside the club during the shooting but said they weren't sure if the footage would be useful.
Police roped off a huge area of the nightclub's parking lot as 60 detectives questioned hundreds of witnesses. Police brought in buses to keep the witnesses warm as they waited.
Witnesses described the gunman as a heavyset man, wearing a Columbus Blue Jackets hockey jersey.
Calvin Bota said he saw the shooting from the mosh pit in front of the stage shortly after the band began playing.
"Somebody came -- I don't know where they came from, out of the audience or whatnot -- but they come onto [the] stage and ... he shot the guitarist at first, fired a couple of other shots and then he hid behind the stage a little bit," Bota told CNN affiliate WSYX.
"Everybody started scattering, you know, there's mayhem everywhere. And then a police officer came into the building, you know, came in professional with his gun raised, and then he proceeded to shoot the guy."
Gerald Caudill said the gunman shot Abbott at least four times.
"I was up close to the stage, and I just saw some guy run up on the side of the stage, and I heard some shots and I saw Vinnie fall, and somebody jumped on top of Vinnie, and the guy just stayed around the stage and started shooting other people," Caudill said.
"I saw wounded people all over the place, out in the parking lot, inside," he said. "It just didn't sound like gunshots or anything; it didn't occur to me that something like that was happening."
Mull said Columbus police have responded to previous incidents at the club, including several he characterized as minor as well as a shooting in the parking lot. He said he was unaware of the club's security practices, except that it had no surveillance camera or metal detector.
"They are in charge of their own security inside," he said. "There are times they hire off-duty Columbus police for parking lot security -- we are prohibited by law from working inside a liquor establishment -- but last night there were none."
CNN's Steve Brusk contributed to this report.