The last time defense lawyer Geraldine Gennet and the D.C. police department shared the same public billing, the D.C. Court of Appeals described the union as "less than the finest hour" for the city.

The police department, the appellate court found in the suit filed by Gennet on behalf of an officer, had to be dragged "kicking and screaming to the bar of justice."

Now, a year later, Gennet's name has surfaced again with that of her one-time legal opponent, Police Chief Maurice T. Turner Jr. Gennet, 35, was sworn in last month as the department's new general counsel.

The alliance is one of the strangest to materialize in city government. Not only did Gennett clobber the police department in one of its most embarrassing appellate defeats, but also she has sparred several times with the department on behalf of rank and file officers and had been associated with the American Civil Liberties Union.

"When I first got wind of this I thought it was a joke," said one high-ranking prosecutor who has dealt with Gennet. "I've always viewed her as the antithesis of the law enforcement type. Her legal associates are as about as left as you can get. It all strikes me as a case of strange bedfellows."

Some law enforcement observers interpret Gennet's appointment as a sign of Turner's frustrations with the chronically troubled administration of police personnel policies that Gennet seemed so adept at picking apart from the outside; Turner may feel, they say, that Gennet can do her revamping as well from the inside. Others, decidedly in the minority, speculate that hiring Gennet is one way of stifling the opposition.

"I think when a client turns around and hires a lawyer that beats them silly, that's a smart client," concludes Arthur B. Spitzer, legal director for the ACLU's Washington chapter, where Gennet was a member of the legislative committee until her appointment.

For his part part, Turner simply said: "Geraldine beat us in court and now she's on our side . . . . We just hope that she will do the same thing for the police department that she did in her private practice."

Gennet characterizes her appointment to the $65,900-a-year position more bluntly: "The police department is doing what many corporations do in the real world. They raid the other side. Instead of being small-minded, the government finally got smart."

As for her criminal defense orientation, Gennet said she now reads "some of the stuff coming out of the Supreme Court, and I get sick. Police officers generally get thrilled. In this job I still don't have to get thrilled, but I can make sure the law is being administered fairly."

Gennet is popular with rank and file police officers, who view her as someone who has represented several officers in their administrative battles with the police department as well as being a tough criminal advocate.

In addition to winning the appellate decision in which the court found that the department violated its administrative policies, Gennet represented a number of police recruits who recently challenged drug urinalyses. In another case, she was on the other side of police officers when she represented private guards who unsuccesfully sought to prevent police officers from moonlighting as guards.

"As a defense counsel Gennet argued very effectively on behalf of her clients, often to the dismay of our officers," said Gary Hankins, spokesman for the Fraternal Order of Police. "But I have to look at her ability and think of it as a plus when it comes to our side. Now she's working for the police department. We're not asking her to ditch her philosophy, but we think she will get a new perspective when she sees it from our side."

Gennet says she began lobbying actively for the general counsel's job a couple of years ago after concluding that she would like to have "more effect than on a case-to-case basis."

"I spent a lot of time with individual officers going down to the police department and saying, 'You did this wrong and you did that wrong,' " said Gennet. "They'd laugh at me and then see me in court . . . . My basic axiom has always been: If you treat people fairly, you can get rid of those you need to get rid of. You don't need to violate your policies."

A major part of Gennet's work will be interpreting Supreme Court and appellate court decisions quickly and clearly so the officer on the street knows what will stand up in court. Police officers long have complained that the general counsel's interpretations are so general and abstract that they are of little practical use.

"As a defense lawyer, I'd see police officers in court who were not up to snuff on what they could or could not do legally," said Gennet.

"Gennet is a wise and excellent choice," said District Court of Appeals Judge Theodore R. Newman, who wrote the appellate opinion criticizing the police department. "As I said to the chief of police at her swearing-in, Ms. Gennet is the type of lawyer who has the courage to tell her client what he needs to know whether her client likes it or not.