METHUEN — Police said a man who broke into a Methuen home and severely beat an 86-year-old man left something behind that helped identify him.

Blood samples taken from a cellar window and door of a house on Taylor Street were sent to the state police lab where investigators matched the DNA to that of a Haverhill man with a criminal record.

Keith Haggar, 36, of 48 Green St., Haverhill, was arrested Wednesday. He was charged with home invasion, assault to maim, mayhem, and assault and battery with a dangerous weapon on a person over 65.

He is being held without bail at the Middleton jail until Wednesday when he is scheduled to be arraigned in Lawrence District Court.

Prosecutors will ask for a hearing to determine whether Haggar poses a danger to the community and should remain in jail pending his trial, said Steve O’Connell, spokesman for the Essex district attorney’s office.

Police declined comment on Haggar’s criminal record but said they learned he was on probation out of Haverhill District Court and his DNA had been entered into the state’s database.

The elderly victim told police he was awakened about 3:30 a.m. on Feb. 11 by his barking dog and got up to see what was going on.

He told police he heard noise from his cellar, and when he unlocked and opened the cellar door he was hit in the face with a hard object.

He was knocked to the floor where the attacker continued to punch him in the face, police said.

Police said the victim had to have reconstructive surgery on his face.

Methuen Detective Lt. Michael Pappalardo said yesterday the investigation continues and he could not comment on the weapon police believe was used in the attack.

Detective Richard Pilz, who investigated the attack along with Pappalardo and Detective John Cushing, also used DNA evidence to identify a man who broke into the Berkeley Shoe Store on Broadway in 2005, in which $50,000 in watches and gold jewelry were taken.

Pilz removed the door from a cabinet in the store where he had found blood evidence, the only clue to the crime, and then waited for two years for the evidence to be processed by the state police crime lab.

The evidence led to a 34-year-old Lawrence man who was in jail on other charges.

Pilz said yesterday he was even more gratified by the DNA outcome in the home invasion case.

“I was ecstatic,” Pilz said. “Even more so in this case because there was an elderly victim involved. The victim was severely injured. ... The victim has not been the same since the attack.”

Pilz acknowledged the lengthy wait in both cases for DNA results to be provided.

“The state lab is extremely backed up and must establish priorities,” he said.