The blackboard in the Arlington Police Department's 1st District squad room says it all: "1D: where the girls are."

For the first time in the county's history, a key section of the police department--the 24-member squad that patrols the northern section of Arlington--is being run entirely by women.

Capt. Becky Hackney and her two lieutenants, Gay Hayslett and Mary Gavin, have more than 50 years on the force among them, including tours as detectives, motorcycle police and school resource officers. Their simultaneous arrival reflects a slow but dramatic change in the culture of police in general and the Arlington department in particular, officers said.

When Hackney, who gives her age as 40-something, joined the force in 1979, she was Arlington's 18th female police officer. The old police offices had only 10 lockers for women--planners apparently never thought they would need more.

Now there are 58 women on active duty, and they make up 16 percent of the 354 sworn officers and six of the 20 lieutenants.

Arlington Police Chief Edward A. Flynn said he welcomes the change. "Any profession is going to be improved when suddenly it opens itself up to half the population," he said. "The majority of our work has always been social work, and large numbers of women in the profession has allowed us to accept that we are doing social work of a very dramatic kind."

Hackney, an Arlington native who has been the 1st District captain for 3 1/2 months, attended Wakefield High School and Brigham Young University before deciding to become a police officer. After tours on midnight and day patrol, she eventually became the sergeant in charge of the motorcycle squad--even though, at the time, she had never even been on a motorcycle.

Naturally, Hackney said, "I decided I had to be on one." She promptly ran the cycle into a curb and broke her nose.

She also took some kidding from outside law enforcement agents when the squad provided escorts to dignitaries. "Outside agencies weren't used to coming on a call and seeing a woman on a motorcycle," Hackney said. "I'd get comments from the Secret Service about the pants and the boots and the leather."

Hayslett, also 40-something, grew up in Arlington and attended Wakefield. She joined the force just after Hackney, after attending Norfolk State University on a partial basketball scholarship.

"I wanted a challenge, I wanted to help people and I was very nosy," Hayslett said.

She is married to a retired Army officer and has two young daughters. Hayslett has done several tours as a detective--including being the first woman on the robbery-homicide squad. Her first day on that job, the male officers told her to make coffee. But she made such awful brew that they gave up that idea, she said.

Hayslett, who has been on the force for 19 years, also heads the honor guard, which goes to community events and funerals.

As one of only a few African American women on the force, Hayslett said she feels she has to perform especially well. "I feel more pressure to set my goals high, to be a role model for blacks as well as women," she said. "I'd also like to recruit more [black women] so I won't be a dying breed."

At 37, Gavin is the youngest of the trio and the most recent arrival in the 1st District--she switched last week from the 2nd District. She grew up in Fairfax County and attended Woodson High School and Eastern Kentucky University. She is married to another Arlington police officer, and they have two young daughters. During her 13 years on the force, she has served as a school resource officer, been on patrol and taught physical fitness and defensive tactics at the police academy.

As a female police officer, Gavin said, she has found that "if you can keep up with [male officers and cadets], they're less likely to harass you. I can keep up."

Though being an all-female command group has drawn quite a bit of attention to the 1st District, Hackney said the squad's main focus will be community policing, not women's rights or accomplishments.

"I'm committed to . . . being an active participant in having the community police themselves," she said. "When we used to [just] do 911 and traditional policing, we never accomplished anything. We'd have to go back to the same addresses with the same issues."

Unlike the three other districts, Hackney's squad assigns an individual officer to each community or neighborhood association, so that residents have a specific person to contact when they need help or information.

"We're trying to educate the community that there are other ways of dealing with problems besides calling the police [to arrest someone], and we can help them problem-solve," she said.

CAPTION: Capt. Becky Hackney, right, chats with Lt. Mary Gavin at police headquarters in Arlington. Hackney, Gavin and another female lieutenant, Gay Hayslett, form the command group in the 1st District's 24-member squad--a first for female leadership on the county's force.

CAPTION: "I wanted to help people," said Hayslett, right, of police work, as she shares a laugh with Hackney.