A chain saw-wielding man who U.S. authorities allowed to enter the United States boasted he was a "trained sniper with over 700 kills" and refused to return to Canada for a court date, a top U.S. customs official revealed Friday.

But William Heffelfinger, deputy assistant commissioner for field operations for U.S. customs, said there was no legal reason to detain the man, who later became a suspect in the grisly murder of a couple in Canada, despite his talk of a violent past.

"They had no reason to charge him with anything," Heffelfinger told The Associated Press in a telephone interview. "There was no crime that he committed. We did not allow him to leave the port with the chain saw, the sword, the braceknuckles or the handcuffs -- all of that we seized. So when he left the port he wasn't armed with anything."

Gregory Despres (search), 22, arrived at the U.S.-Canadian border (search) crossing at Calais, Maine, on April 25 — the same day he was to be sentenced in Canada on charges he assaulted and threatened to kill his neighbor's son-in-law.

The next day, a gruesome scene was discovered at the neighbors': The decapitated body of a country musician named Frederick Fulton (search), 74, was found on Fulton's kitchen floor. His head was in a pillowcase under a table. His common-law wife was found stabbed to death in a bedroom.

Canadian police and U.S. customs officials didn't know about the alleged murders when custom officials let Despres into the U.S., and he refused to turn back to face assault charges.

"We knew he was supposed to be at court," Heffelfinger said. "There was an RCMP [Royal Canadian Mounted Police] officer at the port at that very time and he would not go back to court."

Heffelfinger said U.S. Customs held the man for about three hours. "At certain point it turns into an arrest and we had no reason to arrest this person," he said.

Asked whether Despres' bizarre statements caused authorities alarm, Heffelfinger said that was no reason for police to arrest him or track him from the border.

"He said a lot of things. He said he was with NSA. He was with the Marine Corps, a trained sniper with over 700 kills," Heffelfinger said.

Asked if it was a mistake to let him go, he said: "No. I couldn't make that judgment."

Despres was arrested April 27 after police in Massachusetts saw him wandering down a highway in a sweat shirt with red and brown stains. He's in jail in Massachusetts on murder charges, awaiting extradition.

Bill Anthony, a spokesman for U.S. Customs and Border Protection, said the Canada-born Despres couldn't be detained because he's a naturalized U.S. citizen and there was no warrant for his arrest.

Anthony said they fingerprinted Despres because "obviously you don't want somebody like that walking out of the port into your community where your officers live and your children play."

Colin Kenny, chairman of Canada's Standing Senate Committee on National Security and Defense, said Friday that U.S. customs should have at least alerted police in Maine to keep an eye on Despres.

"I think I would have wanted to keep a close eye on that fellow for awhile," Kenny said. "The whole thing gives me a queasy feeling."

A man named Eddie Young said he sat next to Despres at the customs office when the agents processed them, telling the New Brunswick Telegraph-Journal he heard Despres tell custom officers he was a trained killer.

"That's the reason I remember him. He said he was an assassin," Young was quoted as saying. "When he came in they opened his bag up and they took out, it looked like large bayonets to me but they could have been a little bit longer for swords, and then two pairs of brass knuckles fastened on to his bag, a chain saw and what looked like a flak jacket, a bulletproof vest."

Young said customs officers appeared to be joking around with the swords.

"I watched the Customs guys fling the swords around in the back room," Young said. "I mean, wouldn't the evidence be ruined with their fingerprints?"

Young said officials treated Despres well. "When I came back in they were giving him a coffee," Young told the newspaper. "He got processed faster than I did."

Young said he was detained at the border because he was arrested in Ottawa almost 20 years ago for drug possession.

Despres seemed intense, Young said.

"I'm going like, Jesus, he's an assassin? Like, 130 pounds, nasty looking little Mohawk. I don't even think he blinked for the 25 minutes we were sitting beside each other," Young said.