WARREN, Mass. (WPRI) — The case of a Massachusetts lifeguard who disappeared more than 20 years ago remains unsolved, according to the Worcester County District Attorney’s office.

At a press conference Tuesday, District Attorney Joseph D. Early Jr. said the case remains active and has many “moving pieces.”

Early believes sufficient evidence points to Frank Sumner, who died in 2016.

“Can I rule out anyone? No,” Early said. “But Frank Sumner is a person of interest, that we’re very comfortable naming a person of interest based on, like I said, very persuasive and convincing evidence.”

Sumner was well known to authorities and was named a person of interest in 2021. He lived in central Massachusetts from 1960 through his death. He also operated auto shops in Spencer, Leicester, and Worcester, according to officials.

Bish’s disappearance was first thought to be a drowning, which led to contamination of the crime scene.

“They went looking for clues, people who weren’t detectives,” Early said. “Is her bathing suit here? What’s here? Where could she be? They went into the water. Things were moved around.”

Early said more DNA evidence will be tested soon, but did not comment on the nature of that evidence.