A local real estate appraiser has been sexually assaulting young men for the past 10 years — targeting some victims during “beer pong” tournaments at area bars, Montgomery County police said Tuesday.

“It’s a horrific sexual assault case,” said Montgomery Assistant Police Chief Russ Hamill. “This is a sexual predator.”

The suspect, Joey Poindexter, 38, of Gaithersburg, was being held Tuesday in the Montgomery jail on $500,000 bond. His attorney, Alan Drew, declined to comment.

Hamill said detectives have identified four victims and think there are at least six more based on images recovered from the suspect’s phone. “Our victims become highly intoxicated or possibly drugged — we are investigating that — and then he takes advantage of them,” Hamill said.

Police said that in at least some cases, he took the victims he met in bars to his home, where he assaulted them. The victims whom detectives have interviewed said they are heterosexual and do not have sex with men.

Montgomery detectives also are looking into the possibility that Poindexter traveled out of state looking for victims, particularly at events where “extreme sports,” such as skateboard and BMX bike competitions, take place. The detectives have contacted their counterparts in Virginia Beach, Atlantic City, Las Vegas and elsewhere.

Locally, it appears that Poindexter focused on beer pong gatherings, police said. The game is played by contestants who try to toss table tennis balls into cups that are partially filled with water or beer. It is a common drinking game in college, where it is often seen as a means of getting drunk.

But beer pong also has a competitive side, and the game is played at bars in a manner more akin to darts. There are weekly tournaments and even a Maryland state championship. Poindexter excelled on this circuit, where he met at least three victims, according to authorities. And it was through the beer pong connection that the case broke for police.

On Oct. 3, a man went to a police station to report an odd series of events, starting the day before, authorities said. He said he had gone to Looney’s Pub in College Park, where he played beer pong, drank several beers and met a man who bought him an Long Island Iced Tea, a potent mixed drink.

The man told police that he had no memory of events after the Long Island Iced Tea until the next morning, when he woke up in a house in Gaithersburg, on a sofa, in another man’s black Nike shorts, and with his own clothes next to him on the floor. The resident of the house drove him home, the man said. Believing that he might have been sexually assaulted, he reported the incident.

Detectives quickly learned that the Gaithersburg resident was Poindexter — based in part on his having given the other man his phone number — and set about to catch him in incriminating statements, according to a police report.

After monitoring a phone conversation and a face-to-face meeting between the man and Poindexter, police arrested Poindexter, who later admitted to having sex with the man.

Detectives also confiscated Poindexter’s computer and cellphone, and they found images of other possible victims. Police said the victims’ ages range from the late teens to early 20s.

As for the broader world of competitive beer pong, a group in Maryland — known by its Web site, www.mdbeerpong.com — organizes weekly events, ranks players and holds a state championship. Poindexter was a regular, and even competed in national events, according to online tournament results and friends.

The Maryland group holds weekly matches Wednesday nights at Looney’s Pub. There is no forced drinking during the games, and people who play beer pong, as a group, are no different from those watching TV in the bar or chatting with one another, said Ryan Keyser, an assistant manager who works Wednesday nights at Looney’s.

Keyser said Poindexter showed up weekly for the matches, generally just a few minutes before they started. “He played beer pong,” Keyser said. “That was the only night he was here. He was strictly here for beer pong. He was obviously into the competition of it.”

Poindexter was good, and he generally won the contests at Looney’s or came close to winning, Keyser said. Poindexter appeared to be a quiet, reserved person, Keyser said.

Ata Ehdaivand, a friend of Poindexter’s, met him while playing beer pong at a bar. He said that competitive players consider beer pong comparable to darts or bowling. “It’s exactly the same,” Ehdaivand said. At big tournaments, it’s not unheard of for winners to collect $5,000, Ehdaivand added.

Ehdaivand said he doesn’t know anything about the criminal case other than what the police are saying. Ehdaivand said that his time with Poindexter has always been positive, and he described him as a guy who was quick to joke around and who liked to talk about NBA basketball.

“He’s a really nice guy,” Ehdaivand said. “There’s not one of his friends who won’t tell you he’s a super-nice guy.”

Police ask anyone with information about Poindexter or the case to call 240-773-5070.

Jennifer Jenkins contributed to this report.