When Bernard Crooke became chief of Montgomery County's demoralized and divided police department he had no illusions that the job would be easy. "This is a burnout profession . . . ," he said. "I hope I last five years. But who knows?"

As it turned out, Crooke lasted. Entering his fifth year in the job, Crooke, 50, is ensconced in his $67,682-a-year slot as chief of the Washington area's fourth largest police force, located in one of the wealthiest and best educated communities in America.

"When I was here for two years they still called me 'the new chief,' " Crooke recalls with a smile. "I'll always be an outsider in a way. I'll tell you one thing, my successor will be a Montgomery County police officer. But the jury's still out on this one."

Indeed, not all has gone smoothly for Crooke, who retired as the number two man in the District police department to become chief in his home county. The 775-member force he was hired to soothe after the turbulent two-year tenure of liberal Chief Robert J. diGrazia is split in its attitude toward him. Minority officers have sued him, alleging discrimination, and the local Fraternal Order of Police chapter has charged he damaged department morale by arbitrarily ending the four-day work week.

"Once you destroy morale it takes a long time to rebuild it," says county FOP President Walter Bader, a critic of the chief.

The Montgomery police department's off-again, on-again arrest of Rep. Louis Stokes (D-Ohio) on charges of driving while intoxicated was an embarrassment, and Crooke's announcement that the arrest of Timothy Buzbee, later convicted of two rapes in Aspen Hill, had solved the case was questioned as an infringement of Buzbee's pretrial rights.

Crooke says these incidents are the routine pitfalls of being a police chief: "It's like walking on thin ice with one leg up in the air."

And that stunt, say Crooke's bosses and many of his officers, is one he has performed well. Montgomery County Executive Charles Gilchrist hired Crooke without consulting local police, who were backing an in-house candidate. Now, Gilchrist and County Council members say Crooke has done just what he was hired to do--calm an agitated force, meet tighter budgets without complaint or drastic cuts in services and, perhaps most important, strike a reserved public image in contrast to the outspoken diGrazia.

Crooke has accomplished these goals with a cool demeanor, the efficient style of a bureaucrat, rather than the exuberance of the street cop he once was. In his staged news conferences, the handsome Crooke has cut an authoritative figure, as he did on television last year when a former IBM employe staged a seven-hour siege of the company's Bethesda offices. Behind the scenes, Crooke has a disarmingly candid style. Relaxed and likable, he believes in crisp uniforms, short haircuts and direct answers.

"The policeman's policeman," Gilchrist says of Crooke.

"A traditional police administrator . . . ," says Bader. "A bureaucrat."

"He's a helluva nice fella. He calls me by name," says a sergeant in the Wheaton youth division, where the chief drops in almost monthly. "He's kept the majority happy."

Crooke took office in 1979, following the brief and volatile tenure of diGrazia, who won a national reputation as an innovative police chief in Boston and St. Louis County, but who angered police and Gilchrist in Montgomery. DiGrazia once, for instance, announced that police "view the community as the enemy," a remark that brought an immediate public outcry. Gilchrist eventually dismissed diGrazia and hired Crooke, who as an outsider was viewed skeptically by some officers.

Although Crooke was not a Montgomery policeman when he took charge, he was no outsider when it came to the tightknit and sometimes insular world of police. The job runs in the family--Crooke's father was a cop and his 21-year-old son wants to be one. And in 1957 Crooke started his career like any other naive rookie. "I was gonna be the knight on the white charger and save girls," he recalls. "The first arrest I made, a guy spit in my face."

Crooke paid his dues--from street cop to detective to commander of the city's crime-ridden 3rd District, where he was once mugged, to assistant chief in charge of the day-to-day operation of the District's 5,700-member police force. Those credentials muted criticism in Montgomery, giving Crooke a chance to prove himself.

Some of his early moves did just that. A month into his job, more than 400 officers were given promotions or pay raises and an unpopular diGrazia proposal to end traditional military ranking in the department was killed.

Crooke also inherited a headline-grabbing sex scandal in which male officers were accused of having sex with women while on duty. Crooke diffused the public controversy quickly, imposing 21 fines ranging from $300 to $500 while praising the department as a whole.

"He came in knee deep, but he handled it fairly and quickly, which was important at the time," recalls Sgt. Steven Hargrove, a 16-year veteran.

But the honeymoon didn't last. In 1980, household burglaries in Montgomery jumped by 36 percent, robberies rose 42 percent. In affluent Montgomery, the figures brought a rapid--and with his police unpopular--response: Crooke and Gilchrist hosted a news conference and promised that more officers would hit the streets during peak crime hours. That meant an end to the department's long-sacred four-day work week schedule.

"It was dropped like a bomb one day," Bader says. "It turned a lot of the force against him." This year, the four-day schedule, in which officers work 10-hour days, was reinstated as part of the force's first official labor negotiations.

Jokes Crooke, "If crime goes up, I won't blame it on the four-day work week."

Still unresolved is the lawsuit filed against Crooke and the county in March by the Coalition of Black Police Officers. In a county that is 9 percent black, the department has 43 black male officers, who make up 5.5 percent of the force, and nine black female officers, who compose 1.15 percent of the department. None of the black officers ranks above sergeant. No blacks hold high-level positions in the county police training academy, or in the research and planning or internal affairs sections of the department.

The suit contends that the county is violating the federal Civil Rights Act of 1964 and asks back pay, retroactive seniority and a timetable for promoting blacks in the department.

"He Crooke is not a champion for minority recruitment, promotion or retention," says Tony Fisher, a black detective. "It's been consistent for the past seven years."

Says Donald Jones, attorney for the group, "Blacks have an extremely high attrition rate at the academy and there are no full-time black instructors. It's a white-run academy," where he says the department bias against blacks begins.

Crooke disagrees. Blacks who dropped out of one recent academy class, he says, did so because they failed the necessary tests, even after being coached on what to study for makeup exams. Crooke says he plans to assign a black instructor to the fall class.

Crooke says the department also has tried to recruit more than the four Hispanic officers now on the force. But the search has been difficult, he says, partly because officers are required to have 60 college credits. "The police occupation is not held in high esteem where they come from," Crooke says of Hispanics. "It's a social thing."

Despite the criticism of Crooke, County Council members call him a top-notch administrator. "He's been very strong in defense of his men," says council member Neal Potter. "While they gripe, he does a great job of seeing they're well taken care of . . . . He's a genial, bright man."

Much of Crooke's success is owed to his personality. Though he is reticent to talk about himself and is universally described as "low key," Crooke is quick to smile and regularly cracks dry and often self-deprecating jokes. He says, for instance, that he was born in "1933 on Memorial Day in Washington, D.C., during a vicious spring thunderstorm. My mother said she knew she'd given birth to either a demon or a saint."

That sense of humor also comes in handy at work. In Crooke's first summer as chief, for example, a department slide show presented to county police officials was interrupted for a fleeting moment by a slide of a nude woman. From the mostly male audience came a round of laughter and wisecracks. Not everyone was amused, however, and one sergeant sent an angry memo to the chief. "As if the slide display was not enough, the childish bantering that followed only added to the embarrassment," the sergeant wrote.

An apologetic Crooke responded that he regretted the incident, adding, "I regret further that I also added a comment to the 'childish bantering' that followed."

Crooke, recently remarried, has four children from his first marriage. He looks younger than his years. His body is wiry, his brown hair slightly gray. He wears wire-rimmed glasses, jogs and plays golf and basketball. He draws slowly on a pipe, shifts comfortably behind a desk in his Rockville office and exudes the cool confidence of the ultimate television cop, Frank Furillo of "Hill Street Blues".

"Cool calmness on the outside screens the turmoil within . . . ," Crooke says of himself. "On homicide they said the more pressure I'm under the calmer I seem." Says Crooke of his handling of the IBM siege, "Sometimes you sit back and act cool and collected when you don't know what to do."

Comments like that have won Crooke a reputation for candor. "Over the years it's helped much more than it's hurt," Crooke says of his directness. "There are times I wished I'd kept my mouth shut. People assume I'll come right out with what I'm thinking. There's no big mystery about me."

How long before Bernard Crooke burns out in this job? "There's times I need to take the afternoon off and go play golf," he says. "Maybe one or three years from now these little menders may not work. Then I'll know I'm burned out. Right now, an afternoon of beating a golf ball around the course works wonders."