(NewsNation) — The attorney representing victims of an alleged Long Island serial killer claims evidence connects suspect Rex Heuermann to the cases of Shannan Gilbert and Karen Vergata, who were found dead on Long Island in 2011 and 1996, respectively.

Former FBI agent Jennifer Coffindaffer told NewsNation’s Chris Cuomo on Wednesday “there’s a lot of corroboration that can be done” to verify the new claims.

One of the witnesses who spoke with the attorney, John Ray, said she had previously encountered Heuermann at a well-known swinger’s club near Heuermann’s Manhattan office.

The witness told Ray she went to Heuermann’s home with her boyfriend after seeing an advertisement at the club inviting swingers to a Massapequa Park home. Once they arrived, the witness claims she was greeted by Heuermann and a woman believed to be his spouse, Asa Ellerup.

When the witness and her boyfriend were leaving, she claims another woman, identified as Vergata, was seen running out of the house naked.

“This is the first we’ve really heard about interaction with the wife being involved in anything other than those hairs” found on victims Heuermann is accused of killing, Coffindaffer said.

Heuermann, 59, has been charged in connection with the deaths of three women whose bodies were found in 2010 and 2011 along a stretch of highway on Long Island’s Gilgo Beach: Melissa Barthelemy, Megan Waterman and Amber Costello.

Police said strands of hair matching Heuermann’s wife Asa Ellerup were found on some of the bodies, which is partially how they were able to link him to the crimes. Ellerup has not been charged, and the Suffolk County Police Department previously said Ellerup was not in town during the time of the killings.

“(The witness) needs to describe that interior of the house … describe Asa — what does she look like, what was she like? There’s ways to corroborate the story,” Coffindaffer said.

Another woman, who was working as a cab driver at the time, said she had a disturbing encounter with Heuermann at a motel she was called to by her dispatcher.

She told Ray she saw Heuermann in the parking lot, and moments later, a woman came out of a room crying. The cab driver identified the woman as Gilbert, who she then drove to a local train station.

Heuermann has pleaded not guilty and has been held without bail at Suffolk County Jail in Riverhead.

NewsNation digital producer Sean Noone contributed to this report.