On a chilly January night, cloaked in full disguise and shielded by the cover of darkness, he roamed the streets of downtown Petaluma, keeping an eye out for trouble.

Often eliciting cheers and high-fives from residents familiar with his mission of inspiring goodwill in those he passes, on this particular evening the young man known only by the moniker "Petaluma Batman" zipped through the streets on an electric scooter, posting flyers about his former Casa Grande High School classmate, the then-missing Alyssa Byrne.

"I truly believe that anyone can be a hero," said the 19-year-old as he taped a flyer to an electric pole and then waved to a car full of young people honking as they drove past him on Kentucky Street. "There's a lot of tough stuff going on around the world, so I wanted to do something to boost people's morale."

Petaluma Batman, who wished to keep his identity a secret to protect his family's privacy, has become a Facebook sensation almost overnight. He created a Facebook profile on Dec. 22 just to see how many Petalumans would "Like" his page. Within days, his page had more than 2,700 followers. He has already made a radio appearance, been recognized all over town by random passersby, exploded on social media and been on the lips of countless young people throughout the area.

"I had no idea it was going to take off like this," he said. "But I think it demonstrates the idea that anyone can inspire goodwill."

By day, this self-described"Average Joe" is a typical college student. The tall and wiry teen wakes up in the morning and pours himself a bowl of cereal, which he scarfs down quickly before getting dressed for class at Petaluma's Santa Rosa Junior College campus. He then sits through business courses all morning, before heading to his job at a local golf course.

But as the sun sets, the student sheds his normal life and adopts the persona of Petaluma Batman. He slips into his homemade costume of black pants, a black T-shirt with a shiny, black Batman emblem over the top of a black, long sleeve thermal and sweatshirt. A yellow belt, black thermal gloves and a Batman mask and flowing cape complete his ensemble, allowing him to begin his undercover rounds at the centrally located Petaluma Historical Library & Museum on Fourth Street.

Regular people dressing up like superheroes is not a new phenomenon. They've cropped up from Seattle, Wash. to Bar Harbor, Maine, sometimes causing issues for actual law enforcement. For instance, in Seattle, a 10-member costumed crew attempts to prevent crime led by a man called Phoenix Jones, who reported being stabbed while trying to intervene during a fight between a known drug dealer and a citizen.

But while Petaluma Batman wears the markings of a crime fighter, he says he's anything but. "I am in no way trying to get in front of the police or trained law enforcement at all. They keep a tight lock on everything," he said. "I'm not trying to stop crime personally. If I see something going on, I'll let the trained authorities know, rather than take justice into my own hands."

Instead, Petaluma Batman sees himself as a regular person using the guise of an iconic figure to inspire comfort and goodwill in the community. He said he wants to show people that anyone can make a difference. His purely harmless status has garnered him some celebrity among local law enforcement. Petaluma Police Lt. Tim Lyons, who first heard about the city's "superhero" from his 13-year-old teen, said that none of the Petaluma officers have had cause to take issue with him so far.

"We would only be concerned if he takes any action and gets involved himself," said Lyons. "But if he's just walking around, staging fake fights and having fun, we're fine with that."

Even City Councilmember Gabe Kearney has caught Petaluma Batman fever, following his Facebook page and watching his videos. "I think that anyone trying to help the community is a good thing," said Kearney. "To do it while bringing some comedic relief is an added bonus."

Petaluma Batman said that when he patrols the streets, local officers give him the thumbs-up and tell him he's doing a good job. The public also seems taken with him. As he walked down Petaluma Boulevard North Thursday night, two teenage boys cheered for him as they passed, excited at their brush with a local celebrity. According to Petaluma Batman, he recently encountered a group of 13-year-old boys and girls who had been searching for him. Several girls burst into tears when they found him, begging to have their picture taken next to the lanky teen. "That must be what Justin Bieber feels like," he joked.

As his fame spreads, Petaluma Batman says he is hoping to host some charity events, including city cleanup days, and some events for the Phoenix Theater. He already volunteers — out of costume — with the Special Olympics. He's also hoping to walk in this year's Butter and Egg Days Parade. Most of all, he's hoping to contribute some positivity to Petaluma.

"When I'm not in my Petaluma Batman costume, I hear people talking about me a lot," he said. "It's weird, but I'm glad that I have been able to entertain people and lift their spirits. I just want to inspire some good will."

His thinking seems to be catching on. Just last week, one of only five friends who know Petaluma Batman's real identity emerged from the shadows dressed as Petaluma Joker and engaged in a mock battle with Petaluma Batman, to entertain a crowd that had gathered on the street. Bystanders laughed at the spectacle and seemed to take great pleasure in the hometown show.

(Contact Janelle Wetzstein at Janelle.wetzstein@arguscourier.com)