Shortly after William Trussell became chief of detectives last September, a gag began to take shape in the homicide squad office at the District of Columbia's police headquarters.

"Make sure you get aerial photos in this case," one detective would say to another. "Sure, it's a murder in a basement, but you know how much the chief likes aerial photos."

The gag stems from Trussell's insistence in at least two homicide cases on obtaining aerial photographs despite the belief of veteran detectives that there was no possible use for the photos.

"Yeah, that's funny. I suppose," a homicide detective said last week. "Funny if that were the only time and if it weren't so serious."

Trussell, the controversial chief of the Criminal Investigations Division, is the target of allegations by homicide detectives that he is incompetent to run the division and that he has made a racial slur.

The detectives have listed more than two dozen complaints about Trussell's handling of major homicide cases. They have charged for example, that he "contaminated" a suspected murder weapon by handling it at the scene of a crime and that he interviewed possible suspects and witnesses at a crime scene without making a written record.

Interviews with a wide range of police officers indicate that Trussell's conduct in directing homicide investigations has made him a kind of comic figure among some officers within the department, the focus of biting humor as well as serious criticism.

Yet not all police officials share these feelings and some express puzzlement about the controversy. Trussell was described variously by many present and former high-ranking police officials as "dedicated," conscientious," and "a doggone good official."

One official with long experience both as a detective and as a high-ranking police official said: "I have tremendous respect for Trussell. He's one of the most solid administrators in the department."

Yet another high-ranking official wondered about Trussell's alleged remark equating blacks with animals. "That remark about animals and blacks not going into shock, that's incredible enough for anyone to say, but coming from a guy who thinks he's in the business of investigating violent death, it's incomprehensible."

Both supports and detractors describe Trussell as an articulate, often charming man.

Trussell, a native of West Virginia, is a stout, immaculately attired man, of 51, who carries himself with the easy air of authority of a retired British colonel. His office has the unmistakeable feel of a military command post-clean, uncluttered and dull.

Trussell's service record is a cold account of routine rises to more and more authority. "He was the kind of lieutenant you could look at and know he's going to be a deputy chief," an officer said.

As a policeman and official in uniform for 24 years, Trussell, 51 was a stickler for correct appearance and procedure, and he acquired a reputation as being a hard-liner on rules and regulations.

Trussell had told friends that if once you let a man be sloppy in his appearance, next he'll come in with a shot or two on his breath, then he'll be drunk and then you'll have to pick him up out of the street.

A sergeant who served under Trussell in the uniformed division remembered that Trussell was "a straight, down-the-line, by-the-book man. If regulations said you had to have 15 coats of polish on your shoes, you'd better not let him catch you with 14."

Ironically, it was Trussell's alleged disregard for established investigative techniques and regulations that ignited the homicide squad.

One detective has referred to Trussell in this context as "our Capt. Queeg," a reference to the erratic ship captain of the novel and movie "Caine Mutiny."

"He sends us out chasing rainbows," the detective said, "trying to find evidence to fit his imagination."

Squad members cite an example involving an investigation into a slaying of an elderly couple in their North east home late last year.

"The woman was lying on the bed with her dress up a little bit," one squad member said. "The chief (Trussell) came in, took a walk around and announced: 'This is obviously the work of a 14-year-old sex deviate. You'll find he lives right in this neighborhood." The case is still open, but available evidence points to an entirely different solution, detectives say.

On another occasion, detectives suggested to Trussell that a potential witness be hypnotized in an effort to jog her memory-a technique coming into wide use in criminal investigations. Trussell pronounced hypnotism "voo-doo" and ordered the detectives never mention it again.

Far more serious, the detectives say, was Trussell's handling of the slaying of Pamela Edie, who was stabbed, strangled and bludgeoned in her Capitol Hill home September.

"A medical examiner on the scene examined the body and identified a stabbing weapon found at the scene," one detective said. "Trussell told us that the doctor didn't know what he was talking about, and took the weapon, covered with bloodstains, from a sealed evidence bag, and put it into a paper bag. Then he goes outside where we're interviewing a neighbor, waves the damn thing in his face and says: 'You ever seen this before?'"

Afterward, Trussell told the men that he didn't believe that the medical examiner's office should get involved in homicide cases, the detective said. By law, the police homicide squad acts as the investigative agent for the D.C. medical examiner's office.

The detectives say they also felt that Trussell was constantly insulting them and belittling their work. On a couple of occasions, one detective said, Trussell "remarked that the whole homicide squad isn't worth two internal affairs investigators."

For five years before his appointment as commander of the Criminal Investigations Division last September, Trussell was head of the plain clothes Internal Affairs Division, which investigates charges of wrong-doing by members of the force.

"It was a clash of two different worlds, two different traditions," said one former high-ranking detective official.

"Investigators have got to be allowed to use their unique experience to make judgments. They feel that the para-military notions of the uniform divisions cramps their work, the official said.

"At the same time," he said, "you can't have a guy trying to tell them what to do if he's never done that kind of work before," he said.

Several previous chiefs of detectives who had come to the job from the uniformed ranks had been content to confine themselves to administrative details and to leave the working control of the squads to senior captains.

The detectives remember the last commander before Trussell mainly for having ordered them to wear jackets in the hallways and for noting illegally parked police cruisers that he could see from his office window.

The criminal investigations command includes the robbery, burglary and sex offense squads as well as homicide, but men in the other squads say they almost never see Trussell. According to a robbery detective, Trussell has been in the squad twice in eight months.

A sex squad member said he recalls seeing Trussell in that office only once, and that was to see the new office partitions.

One high-ranking police official described the Trussell controversy as an "unfortunate lack of communication," between Trussell and the squad.

"I know that Bill (Trussell) is a great administrator and the detectives in homicide are great investigators. Somehow they just didn't jell," he said.

On his transfer to the Criminal Investigation Division, Trussell took an immediate interest in the work of the homicide squad, a close-knit group made up almost entirely of experience investigators proud of their nationwide reputation.

"His office is right next door (to homicide) and he was in here damn near every day, fiddling with this and that, telling us how to investigate kinds of cases he never had even seen before," one squad member said.

Trussell's alleged "interference" in homicide cases finally became too much for senior squad Lt. Raymond Pierson, a hulking man with strong opinions. After a heated argument on April 17 about the questioning of a mother of a five-month-old Swedish baby who drowned in a hotel bathtub, Pierson stormed out of Trussell office, not forgetting to slam the door.

Nine days later, Trussell told Pierson that he was to be transferred to the uniform division because he was unable to conform to Trussell's management philosophies. Pierson told Trussell that he considered him the "worst chief of detectives the department had ever had."

The men in the squad responded to transfer by declaring they would also walk out, but Pierson dissauded the, saying that they would accomplish nothing by the gesture and would leave themselves open to "reprisals."

After an intervening weekend, Pierson, a 21-year-veteran, submitted a request for retirement, but was told by Trussell that he would nevertheless be recommended for trial board action. An hour later, the police personel office notified Pierson that his transfer was effective immediately. Pierson left the office in tears.

The homicide detectives were already gathering signatures on a petition of Chief Burtell Jefferson declaring their "collective rage" at the transfer. The revolt was under way. CAPTION: Picture, WILLIAM TRUSSELL . . . target of detectives' complaints