(NewsNation) — Investigators linked a New Jersey lawyer to the sexual assaults of four women in Boston about 15 years ago by retrieving DNA from a drinking glass he had used, prosecutors said.

Matthew Nilo entered a not guilty plea to multiple charges, including three counts of aggravated rape, two counts of kidnapping, one count of assault with intent to rape and one count of indecent assault and battery.

Nilo, 35, of Weehawken, New Jersey, was arrested last week in connection to four attacks in Boston’s Charlestown area from August 2007 through December 2008.

One of the victims was attacked while taking an early morning run. She poked her attacker in the eye with her gloved hand and later gave the glove to authorities.

Using forensic genetic genealogy, police identified Nilo as a person of interest in the four attacks. The FBI obtained DNA from drinking glasses Nilo used during a corporate event and found it was a likely match to the DNA from the glove.

Joseph Cataldo, Nilo’s attorney, called the way law enforcement gathered his client’s DNA “somewhat suspect.”

“It seems that they obtained DNA evidence without ever obtaining a search warrant. If that turns out to be true, that’s an issue that will be pursued vigorously,” Cataldo told The Associated Press.

Nilo’s next court appearance is slated for next Monday.

The Associated Press contributed to this report.