AMITY TWP., Pa. -

Search crews and dogs fanned out Saturday to look for a Berks County man who's been missing for almost a month.

Robert Kosik's mysterious disappearance has stunned his neighbors at the Bel Air Estates Mobile Home. When they discovered him missing in early June, his front door was open, his cat was inside, and his television was still on.

Police said Kosik may have diabetes.

"He could have had a medical issue and walked away from his house," said Detective Jeffrey Smith the the Amity Twp. Police. "We don't know."

Teams of searchers combed roughly 50 acres near the mobile home park on Saturday.

"We're doing our best to see what we can find," said Captain Brent Stouffer, with the Volunteer Medical Service Corps' K-9 Search Team. "It's a lot of ground, a lot of fields."

Much of the area is heavily wooded.

"This person could be -- there's a lot of undeveloped land at this end of the township," said neighbor Bob Yanos. "He could be anywhere."

The 65 year-old Vietnam veteran lived alone, according to neighbors.

Police promised more searches like this.

"The search is going to continue," said Smith. "We're not going to stop until we find him or find his whereabouts."

Kosik is described as being 5 feet, 6 inches tall and about 160 pounds with gray hair and a long goatee. Police said he reportedly walks with a limp.

Anyone with information is urged to contact the Amity Township Police Department at 610-689-6002.