On his way home to Brookland from work downtown one May evening, Todd Allen Keller faced two men on the Metropolitan Branch Trail after they knocked him off his bike and kicked him in the face.

Keller, 41, punched one in the groin, scaring them off. He ended up with a broken wrist — and a determination to make the trail safer.

After a recent rash of crimes on the trail, the work of Keller, the Guardian Angels, a local trail activist and D.C. police has led to regular safety patrols along a 1.5-mile stretch, between Franklin Street NE in Brookland and L Street NE near Union Station.

“When it happened, the first initial thought was, ‘I’m not going to let this go by,’ ” Keller said. “They may have the weapon of fear ... but I have the weapon of community.”

Police and commuters blame area youths who attack and sometimes rob passersby. In one instance, police said, someone tried to use a stun gun on a bicyclist. According to police reports, at least five attacks occurred during evening commute hours between May 5 and June 9.

On May 26, a male threw a metal pipe at a 61-year-old Southeast woman as she walked to the New York Avenue Metro station. The pipe missed, but he punched her in the face and made off with her purse, cash, cellphone, wallet and a Spanish copy of “Moses: The Seer of Sinai,” according to a police report.

The trail is “beautiful,” said the woman, who spoke on condition of anonymity because she was concerned for her safety. But she lamented the presence of “predators” in the area. She returned to the trail last week for the first time since the attack and has promised co-workers not to walk it alone again.

No crimes have been reported since police arrested a 19-year-old on a trail-related robbery and assault charge June 9, according to Sgt. Jon Dorrough, who supervises police patrols on the trail. Investigators hope at least some of the other attacks were committed by the same person.

In the meantime, hundreds of trail commuters and residents have bonded through an e-mail list set up by the national nonprofit Rails-to-Trails Conservancy last year. They use the list to share concerns, plan events and coordinate biking groups for people who no longer want to commute alone.

“It’s a forum for trail users and community members who are concerned about the rail and use the trail,” said Stephen Miller, who works at Rails-to-Trails.

The trail community has attracted the attention of police, and Rails-to-Trails is filming a documentary on its quick-fire response to trail crime.

After Keller was attacked, he met with the D.C. Guardian Angels about patrolling the trail, said John Ayala, head of the D.C. Angels. Miller also approached Ayala around the same time. Ayala’s solution: Round up the locals.

And so Miller reached out via e-mail, publicizing an open house he planned with the D.C. Department of Transportation, which designed the trail, and police. About 75 bikers, runners and walkers stopped by a tent set up at Fourth and S streets NE on June 22, and a few dozen signed up for volunteer patrols.

The Guardian Angels led the first patrol June 26. Three days later, Ayala taught Miller and a group of four commuters how to be Guardian Angels themselves. (Bring water, a pad and paper, a flashlight, a first-aid kit, a whistle and caution: “I don’t want anybody confronting no one,” he said.)

At the end of the tutorial, the participants introduced themselves. Dave Smedberg, 25, said he sometimes uses the trail very early in the morning. Whenever he passes someone, he said, “we make eye contact with each other and nod, so we know that we won’t cause trouble.”

Soon Miller, six veteran Guardian Angels and three newcomers rode bikes along the trail, while Ayala and the others walked the path and looked for overgrown foliage and blind spots so they could warn other trail users about them.

Within a month, Ayala hopes, groups of four will patrol the trail two or three evenings a week. Eventually, he hopes for daily patrols. Dorrough said police might join the patrols as well.

The 61-year-old robbery victim had not heard of the volunteer safety group until a reporter told her about it. She said she’s glad that the Guardian Angels are involved, because “they are taking the path away from those predators.”

Still, some are waiting to see how the patrols work out. Charita Brent, the Advisory Neighborhood Commissioner for the area that includes the top portion of the trail, said she stopped using the trail when she heard of the incidents last month. She plans to join a safety patrol before deciding whether to use it again.

“I’m just chicken,” she said.

Others are less concerned. “This is a city,” said Anica Allen, 29, a trail user from Brookland. “Teenagers do stupid things.”

Mark Plotz, who manages the D.C.-based National Center for Bicycling and Walking, said the Metropolitan Branch Trail community is special because few trails in the region get such attention from local residents and commuters.

“With [other D.C. area trails], there’s not really a community there,” he said. “There are a lot of people who bicycle on it in the evening, and there are bicycling groups. But in the neighborhoods surrounding them, there is no sense of ownership.”