Vowing to curb a rash of violent crimes in Boston this year, nine members of a group of citizen watchmen known as the Guardian Angels began patrolling Dorchester streets during the day and the MBTA Orange Line at nighttime Friday, despite a history of past tensions with police. But the group’s founder and local officials are saying Boston’s college students will most likely not notice the group’s presence.

Curtis Sliwa, a radio talk-show host who founded the New York-based group in 1979 to help combat crime in the streets of the Bronx, said he decided to bring the Angels back to Boston after several former members emailed him months ago asking for help. The group had patrolled Dorchester in the 1980s and 1990s.

“The city desperately needed help,” he said. “People who remembered us wanted us.”

Sliwa said the Angels act as a strong visual presence to deter crime and also make citizen’s arrests and intervene to break up fights – which has proved effective in helping police, Sliwa said.

“In the 1990s, there was a tremendous drop in crime,” he said.

He noted, however, he has had trouble communicating with the Boston Police Department in the past.

“They have chosen not to meet with us or engage in dialogue with us,” Sliwa said. “It’s unfortunate. Why would they want to reject free help?”

The Angels will mostly focus on patrolling Dorchester and then move onto other areas, including Roxbury and Jamaica Plain, when they recruit more members.

He said, however, he doubts the group will ever patrol areas like Allston-Brighton because the severity of crimes in those areas do not compare to the level of shootings in Dorchester. Also, Allston-Brighton community members have not sought their help, he said.

“Interest hasn’t been expressed from off-campus housing or campuses,” Sliwa said.

District D-14 community service officer Dan Daley said few college students live in the areas the Angels will patrol.

“They just walk around and talk to kids and make connections with the kids – tell them it’s okay to give information to help the police,” he said.

Daley said the Angels have no more jurisdictional powers than the local residents they hope to recruit.

“They’re private citizens,” he said. “They can do whatever they want to do as long as they don’t cause a disturbance.”

Boston University Police Department Sgt. Jack St. Hilaire said the group can help the police if it works within bounds and noted the police already collaborate with other existing citizen groups.

“If [their role] is similar to our escort service or similar to neighborhood crime watches, where they’re the eyes and ears for the BUPD and BPD, then I don’t see a problem with it,” St. Hilaire said.