A gunman who killed seven former co-workers and wounded 14 others before committing suicide warned over a period of 20 years he was contemplating the bloody rampage but was not taken seriously, police said.

Joseph T. Wesbecker, 47, of Louisville, fired on his former colleagues with an AK-47 semiautomatic rifle Thursday at the printing plant where he had been employed, then shot himself to death with one of his other four guns."Over a period of 20 years at the company he made statements that he was going to do what he did. But no one took him seriously," said homicide Detective Mark Handy. "People we talked to at the company said it was not uncommon for him to talk like that."

Police said Wesbecker ranged up and down three floors of the downtown Standard Gravure printing plant, firing an undetermined number of shots during a 30-minute rampage, said Police Chief Richard Dotson.

The gunman appeared to choose his targets deliberately as he emptied at least one clip during the shooting spree, said chief of detectives Maj. Edward L. Mercer. "It was not random," he said. "There were no holes in the ceiling."

John Tingle, a co-worker who was spared by Wesbecker, said the gunman earlier threatened some of his superiors on the job. He was "overloaded" with problems and he "had a mental problem to deal with. He felt they were making him do things he didn't want to do."

Tingle said Wesbecker's doctors had told him the chemical fumes from the plant made him sick and he was placed on disability. But in the past two weeks, Tingle said, Wesbecker received a letter from the company informing him that the disability would be canceled.

Wesbecker had gone back to the plant to visit friends during the past year, but Handy said he was not aware that Wesbecker threatened any of his supervisors during those visits.

However, Wesbecker did tell co-workers, both during the time he worked and after he went on disability, that he intended to harm people at the company he did not like, Handy said.

Police Lt. Jeff Moody said Wesbecker entered the building of the printing plant about 8:40 a.m. Thursday, took an elevator to the third floor and shot a receptionist and a second female employee.

He worked his way to the basement, killing five more people along the way, then put a German-made Sig-Sauer pistol under his chin and pulled the trigger, said Moody, commander of the department's physical assault squad.

Mercer said the assailant had at least six 30-round clips of ammunition for the AK-47 when he entered the building.

"I've been a policeman 28 1/2 years and this is the worst I've ever seen," the police chief said at news conferences late Thursday. "It looked like a war zone. Hopefully we will never have another like this."

Moody said Wesbecker had been under treatment for various mental disorders and had attempted suicide at least three times. He said the gunman had no known police or military records.

Besides the Chinese-made semiautomatic assault rifle and the German pistol, Wesbecker carried two Mac-11 9mm semiautomatic pistols, a .38-caliber revolver and a bayonet, Mercer said.

Six people, including Wesbecker, died at the scene. Two others died at separate hospitals. Of the 14 wounded in the assault, five were hospitalized in critical condition and eight were on the stable list late Thursday. One victim was treated for less serious injuries and released.