Wagner appeared at the commissioner's office wearing a gray T-shirt, with a gray beard and shoulder-length gray hair.
Wagner's bail was set at $60,000.
Authorities had confiscated about 20 handguns and rifles and homemade explosive devices by Wednesday afternoon, Newell said.
Maryland State Police, FBI agents, agents from The Bureau of Alcohol, Tobacco, Firearms and Explosives, Washington County Sheriff's Department deputies and the Maryland State Fire Marshal's office arrived to search the home off Eastern Boulevard shortly before 6 a.m. Wednesday, Newell said.
A Baltimore judge signed the search warrant on May 6, according to court documents.
Officers warned Wagner's neighbors to stay inside, Newell said.
SWAT teams from Maryland State Police, Montgomery County and Howard County surrounded the home, he said.
After Wagner surrendered, the state fire marshal sent a robot into the home to check for booby traps. Members of the Pagans have used booby traps before, Newell said.
On Wednesday afternoon, authorities could be seen carrying guns and black boxes from the home.
Maryland State Police troopers seized seven handguns, two explosive devices and 13 long rifles, according to court documents.
Wagner kept to himself and appeared to live alone, neighbors said.
Some neighbors said they heard a motorcycle, but never saw Wagner riding one.
Don Klick has known Wagner since the man bought a house on Antietam Drive about 10 years ago, Klick said.
Wagner was an average guy with a lot of farming equipment who did odd jobs around the neighborhood, Klick said.
"I never saw him on a motorcycle, but I was told that he rode motorcycles," Klick said.
Klick counted nine SWAT team members surrounding Wagner's house early Wednesday morning, he said.
"I think he (Wagner) was a fine gentleman ... with my dealings with him," Klick said.
Klick could not understand why authorities focused their attention on his neighbor, he said.
Wagner has been convicted of criminal charges and motor vehicle violations in at least four Maryland counties. The charges, which include weapons offenses, date back to the 1980s, according to court documents.
In April 1992, Wagner was charged with carrying a handgun in Prince George's County, Md., concealing and carrying a weapon and resisting arrest, the documents state. He was found guilty only of resisting arrest, and the other charges were merged, records state.
He was given probation before judgment in Prince George's County in 1993 for charges of theft.
Wagner also was convicted of assault and of battery in Prince George's County in 1985, court documents show. He was also convicted in federal court of possession of explosives, according to court documents.
The Pagans Motorcycle Club includes about 400 members in 42 chapters and is one of the four largest motorcycle gangs in the United States, based primarily on the East Coast and stretching as far west as Ohio, Newell said.
Less than 50 members of the Pagans are believed to be in Maryland, Newell said. Members have been arrested for violence, illegal firearms possession and drug possession, Newell said.
Erin Cunningham and Andrew Schotz contributed to this story.