Baltimore police have enlisted state troopers to help with patrols as the city confronts a spike in crime, a move that puts to an end years of disagreement between the two agencies over the state force's role in local law enforcement.

With the Maryland State Police now led by a former Baltimore police commander, the agencies began talking about the new arrangement over the summer, and new Baltimore Police Commissioner Anthony W. Batts has pushed it forward as part of his plans to get more officers on foot deployments.

The program, which began in September, pairs troopers with city officers on Friday and Saturday nights. Though troopers have had a presence in Baltimore for decades as part of various task forces, under state law they can only police the city when invited by the Baltimore police.

In Baltimore, political leaders have expressed concern in the past about bringing in an unfamiliar force with its own agenda. The current initiative, both agencies stress, is entirely directed by the city.

While political tangles have hampered past efforts at more cooperation, the current effort faces critics who worry about resources being pulled away from rural areas.

Many Maryland counties depend on state police, who are the primary law enforcement agency in some jurisdictions, and they work alongside local officers in others. Troopers patrol highways throughout the state.

State Sen. David R. Brinkley, a Carroll County Republican, questioned whether the state should be reimbursed for the Baltimore patrols. His county uses a resident trooper program that pays state police to patrol the county, and which state police say they plan to scale back.

"The state police have been struggling with a lack of resources, and in many rural communities, they are the primary force," Brinkley said. "We all have an interest in Baltimore being safe, but in areas where resources are being taken away, where they don't have a city force, that could be problematic."

House Republican leader Anthony J. O'Donnell, who represents Calvert and St. Mary's counties, applauded the move. He said he has long thought the state should use "every asset possible" to fight crime in Baltimore.

Technically, state police are working in Baltimore as part of an initiative to utilize the state force's license-plate reader technology. But they end up getting involved in many kinds of patrol work and have even been walking foot beats.

"We pick a geographic area and we try to target it to areas experiencing some violence, and look for ways that we can use their tag-reader technology," said Baltimore's deputy police commissioner, John Skinner. "They've been in Northeast Baltimore, on Greenmount Avenue, in the Southeast District for robberies. We'll be using them downtown also."

State police Lt. Col. J.A. McAndrew, who began his career as a city officer, pointed to state police deployments for major events or work on a regional task force that serves warrants as examples of earlier cooperation. But he acknowledged that troopers from barracks around the state walking foot beats in Baltimore neighborhoods is a first.

"The state police aren't just wandering around Baltimore," McAndrew said. "We're teamed up, riding with Baltimore City police officers on an organized detail plan, to work on specific days on specific times."

He said the agency sends the officers to Baltimore as part of their normal work duties and the state does not seek reimbursement from the city.

Officials say the initiative is evidence of broader improved cooperation between state and local authorities.

"From the first days of this administration, we have understood that reducing violent crime in our state, including Baltimore City, is a fundamental mission of state government," Gov. Martin O'Malley, the former mayor, said in an interview. "Only the Baltimore Police Department can enforce the law in Baltimore City, but we can play and are playing an important supporting role."

Edward T. Norris, who led both the city and state police, said he faced resistance when trying to get troopers involved in meaningful ways. They balked at his invitation when he was city commissioner, Norris said, and the city rebuffed his interest as state superintendent to expand the agency's authority into Baltimore.

"It was all political," he said.

Some trace the resistance to a high-profile 1994 raid by state troopers on The Block, in which charges against some defendants were dropped because of questionable police practices. An audit of the operation in Baltimore's strip club district showed that officers spent $98,000 on liquor and "amusements."

That raid was carried out only after state police received permission to investigate The Block from the city's acting commissioner.