WORCESTER, MASS. (WHDH) - Investigators on Thursday named a new person of interest in the decades-old murder of Molly Bish, a teenage lifeguard who disappeared while working at a pond in Warren.

Francis “Frank” P. Sumner Sr. is being investigated in the 2000 murder of the 16-year-old after detectives recently received new information, according to Worcester District Attorney Joseph D. Early Jr.

“It’s incredibly relieving to know that my quest to find the murderer is maybe almost over,” said Molly’s sister, Heather Bish. “I’m really just a teacher and I’ve been trying to solve a crime that’s sort of beyond my comprehension for a long time.”

Sumner, who was 71 when he passed away in 2016, was active in Central Massachusetts from 1960 up until his death, Early’s office said in a news release. He was known to operate auto repair shops in the Spencer, Leicester, and Worcester areas.

Bish was a resident of Warren and was working as a lifeguard at Comins Pond on June 27, 2000, when she suddenly vanished. Her disappearance set off a massive search.

Bish’s remains were found nearly three years later in the woods of Whiskey Hill in Palmer.

“To these families, it doesn’t matter if it’s 10, 20, 30 years old. This is just as important as if it happened last week and he emotions still run the same,” said Worcester County District Attorney Joseph Early.

Investigators are now seeking tips from the public about Sumner’s employment practices, associates, vehicles, travel, and habits. Anyone with information is urged to contact an anonymous tip line at anonymous tip line at 508-453-7575.

This is a developing news story; stay with 7NEWS for updates online and on-air.

(Copyright (c) 2021 Sunbeam Television. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

Join our Newsletter for the latest news right to your inbox