BOSTON (AP) — Investigators used advanced DNA technology to identify a suspect in a series of sexual assaults in Boston that took place about 15 years ago, law enforcement officials said.

Matthew J. Nilo, 35, was arrested in Weehawken, New Jersey, on Tuesday, Joseph Bonavolonta, head of the FBI’s Boston office, said at a news conference at Boston Police headquarters.

Four victims were informed of the arrest, he said.

“We certainly realized that identifying this individual does not ease their pain. Nothing can, but hopefully it answers some questions,” he said.

Nilo is charged with three counts of aggravated rape, two counts of kidnapping, one count of assault with attempt to rape and one count of indecent assault and battery in connection with the assaults in Boston’s Charlestown neighborhood in 2007 and 2008. Nilo lived in Boston at the time, authorities said.

It could not immediately be determined if he had a lawyer. Listed phone numbers were either not in service or went unanswered. It was unclear when he will be arraigned.