Authorities are still searching for John Smith, the 73-year-old Norristown man who went missing early Thursday morning.

Norristown Police are now being assisted by Greater Philadelphia Search and Rescue (GPSR), a professional search team of trained men and women using canine partners and teams on bicycles. A local Boy Scout Troop has also joined the search effort. GPSR has set up a command center across from Norristown Municipal Hall at 235 East Airy Street.

According to Mark Hopkins with GPSR, the group is searching wooded areas and parks again (the team was in town on Saturday doing the same) and is expanding the search to surrounding neighborhoods. Because Smith could still be moving, it's important to recheck areas that have been searched on previous days, said Hopkins.

"Usually on the second day, people get comfortable with you," said Hopkins. "Once the realize we're not law enforcement people will come up and give us tips."

It's also possible that Smith has left the Norristown area, said Hopkins.

"This being a transportation hub, it's very easy he's moved out of the area," said Hopkins. "What we're doing is making sure he's not injured or in some other state in this immediate area... We're investigating anywhere he could have possibly [gone.]"

Smith suffers from Alzheimer’s and was reported missing from his home in the 500 block of Arch Street at 7 a.m. Thursday morning.

Smith is described as 6’ tall, 180 lbs. with salt and pepper hair. He was last seen wearing a black fleece sweatshirt and black pants. Smith usually wears eyeglasses.

Anyone with information about his possible whereabouts should contact the Norristown Police Department at 610-270-0977.

GPSR will continue the search until sundown.