SAN MATEO (CBS SF) — Police released new information Thursday seeking help in solving the 44-year-old cold case of Sherry Roach, a missing teen with ties to the Peninsula and North Bay communities.

San Mateo Police released a photograph of a man standing next to Sherry Roach, a 17-year-old girl who went missing in San Mateo in 1976. Investigators characterized the African American man, who appears in the photograph to be in his 20s, as an unidentified person of interest.

Roach is 5′ 5″, white with some American Indian background, has brown hair, blue eyes, and wore glasses. She had ties to both Santa Rosa and San Mateo, police said.

She was reported missing from a San Mateo halfway house that has since turned to a dental office.

Detective Tom Paulin uncovered the photo taken before Sherry went missing. She did not like to take pictures, so it was even more unusual to see a picture of her with a man a few years older.

They heard rumors of a boyfriend, but none of Sherry’s family members recognized the man.

“Not losing sight and continuing to dig and not giving up,” said Paulin. “And that’s what we’re doing here. We’re not giving up. In fact, we’re intensifying the search.”

At the time of her disappearance she was 115 pounds and her teeth were crooked. She may have changed her hair color to blonde, police said.

Investigators also re-released an age-progressed image of how Roach might look today.

“We wish closure for Sherry’s family. Please share this information and help in our efforts to bring attention to this investigation,” San Mateo Police said in a press release. “Someone may have a critical piece of information investigators need.”

44 years later, not a day goes by without Jerry Roach thinking of his older sister, Sherry.

“Maybe she is still alive, which I’m hoping for,” he said. “But I know it’s doubtful, ’cause I think if she was alive, she would have contacted me. Gives me hope to just give us all closure.”

Jerry said they were very close. They grew up in Santa Rosa in a violent household. That forced Sherry to bounce around foster and group homes. One day, the 17-year-old girl just vanished.

When asked what he would say to his sister if he had a chance to speak with her, Jerry replied, “I would ask her why? Why she left or what happened? And [tell her] that I loved her and that I missed her.”

Jerry Roach and his mother still live in Santa Rosa and hope that one day they can reunite with Sherry.

Anyone with information to offer was urged to contact San Mateo Police Detective Lee Violett at (650) 522-7662 or lviolett@cityofsanmateo.org. People can also call the department’s Anonymous Tip Submission line at (650) 522-7676.

Da Lin contributed to this story.