SACO — An autistic man who had been missing for more than 12 hours has been reunited with his parents after he was found tonight in the town of Berwick.

Authorities said that William Webber of Saco was spotted walking through a property owner’s backyard off Route 4 around 7:30 p.m. That home is located about 100 yards from the Amtrak rail line. Earlier in the day, an Amtrak train operator reported seeing Webber walking beside railroad tracks.

Police said Webber must have walked from his home on Hill Street in Saco to Berwick, a distance of approximately 30 miles. Berwick police Officer Bill Russell escorted the 23-year-old back to the police station, where he was reunited with his parents.

“He was in great shape,” Russell said of the young man’s physical condition.

Saco police Cpl. Ken Foss said Webber was discovered missing by his mother around 7 a.m. Sunday. He lives at her home.

Webber is believed to have left sometime during the night. He did not bring his eyeglasses or his hearing aids with him, which raised concerns about his safety.

Police were told that Webber was fascinated with trains and has been known to walk long distances on train tracks.

Foss said Webber has limited language skills. “He’s safe, but we are still not sure where he was going,” Foss said.