The Fairfax County Board of Supervisors yesterday selected Lt. Col. David M. Rohrer to be the county's police chief, following a tradition of selecting chiefs from inside the department but bypassing Acting Chief Suzanne G. Devlin.

Rohrer's appointment ends a five-month search, which included candidates from the District and Jersey City police forces as well as the U.S. Secret Service. Rohrer, a 23-year veteran, heads the department's investigations and operations support branch and was one of three deputy chiefs vying for the vacancy created when J. Thomas Manger retired in January to take the chief's job in Montgomery County.

Rohrer, 47, said his priorities will be preventing gang violence -- a growing problem in the county -- and shoring up the county's preparedness for a terrorist attack. The county's homicide rate is already the lowest among the nation's large localities.

In his interview with the board, Rohrer emphasized his interest in hiring more minorities to reflect the county's changing demographics. The county's population has hit 1 million, and more than one-third of its residents are foreign-born.

Rohrer was sitting in the audience at the Fairfax board auditorium when Chairman Gerald E. Connolly (D) made the announcement. Devlin and Lt. Col. Charles K. Peters, the other two deputy chiefs and top candidates, were sitting next to him and joined in the applause when Rohrer stood to acknowledge the appointment.

Connolly later called the new chief a "policeman's policeman" who leads with a quiet but "firm and determined" style. "He's a steady hand in times of crisis."

Connolly said the supervisors "went through the pros and cons" of the five finalists. "Dave came in No. 1 in judgment, leadership skills and breadth of experience in the police department," he said. "He's quiet. But he laid out a pretty compelling vision" for the department, Connolly added.

County officials said Rohrer's appointment is effective today. His salary will be $137,000 a year.

The other two finalists were Fairfax police Maj. Tyrone R. Morrow and Donald A. Flynn, an assistant director of the Secret Service. The board interviewed Flynn yesterday after he received strong support from the police union.

The board then deliberated in closed session for more than 21/2 hours before emerging with its decision.

Rohrer, with a quiet, unassuming style, emerged as an alternative to Devlin, who would have been the first woman to head the county's police department. More than a decade ago, she successfully sued the department for sexual discrimination and won a promotion. She also had a protracted zoning battle with the county.

When County Executive Anthony H. Griffin announced her appointment as acting chief in January, Connolly said he welcomed the opportunity to consider making history. But in six months as acting chief, Devlin developed some detractors among the Board of Supervisors, who questioned some of her management decisions, including her recent failure to tell board members of visits planned to the county by Attorney General Jerry W. Kilgore (R) and Rep. Frank R. Wolf (R) to discuss gang violence. Connolly said yesterday that the lack of communication was not the deciding factor against her.

"It was a great six months," Devlin said of her temporary tenure at the top. "I had a great time. I have no regrets. Dave is a great guy and will be a great chief, as Chuck [Peters] would have been." Devlin, a 28-year veteran, said she intends to stay with the department.

To some county officers, Rohrer's low-key personality made him a slightly surprising selection over a candidate with more visibility and volubility, such as Devlin. But officers and supervisors reacted with excitement that a "cop's cop," as he was repeatedly described, will take over the job overseeing 1,300 uniformed officers and 500 civilians.

"Our membership is pleased with the outcome," said Officer Josh David, president of the Fairfax police union, which had backed Flynn. "Dave Rohrer has a lot of supporters on the police department. A lot of people really look up to him and respect him."

Rohrer spent a long part of his career as a tactical officer and then as commander of the special operations division, handling such assignments as hostage situations and search warrants, giving him added credibility with patrol officers, colleagues said. He also headed the Fair Oaks District station and was a commander in the patrol bureau before becoming a deputy chief. As head of investigations and operations support, he oversaw Fairfax's role in the 2002 sniper investigation. "He lets you do your job" and doesn't meddle, from above, one member of the sniper task force said.

Like his predecessor, Rohrer worked his way up from patrol officer. But Manger was a former stage actor with a quick wit, while many describe Rohrer as introverted.

Manger said Rohrer would be a "phenomenal chief." He said Rohrer "has the interests of the police department as his primary focus. It's not about him, it's not about an agenda. It's about caring about the men and women of the department. He's a pretty selfless guy."

He also described Rohrer as "plain talking, not a lot of chitchat and politically correct stuff. But put him in front of a roll call and he's going to connect with the troops better than anyone."

Manger, who was consulted by some of the supervisors during the search process, said he endorsed all three of his deputy chiefs.

Rohrer moved to Fairfax County in 1985 and lives in Reston with his wife and two teenagers, 15 and 17, who attend Herndon High School.

Gerald E. Connolly, right, called David M. Rohrer's style "firm and determined."