Lisa Ann Calvo has been missing since 2005 and a $50,000 reward is being offered for leads in the case.
Her family last saw her on the morning of Oct. 6 in New Haven.
She was homeless at the time and had, at times, lived on the streets, police said, but that was supposed to change.
On the day Calvo disappeared, she was supposed to move to her parent’s home and enter a drug-treatment program.
Calvo was known to frequent areas in the city’s Fair Haven District and police said the circumstances surrounding Calvo’s disappearance are unclear and her case remains unsolved.
Police will be holding a news conference on Thursday afternoon about the case and the reward.