Mike McClary remembers it vividly. He has gone over it in his head at leat 100 times trying to figure out what went wrong, why it happened to him.

I happened at 2 o'clock that Oct. 16, a sunny Sunday afternoon. McClary, who joined the D.C. police force eight years ago, and a friend were building a doghouse in McClary's backyard for the family dog, Shawna.

McClary was holding a two-by-four. His friend was splitting it with an electric saw.

As McClary's friend started into the wood, the saw bucked. The next thing McClary knew he could see the bone of his left index finger and blood was gushing from his left middle finger.

In that split second Mike McClary's life changed. In a way, it stopped.

Five months later, McClary still cannot use either of the two fingers and his once bright future with the police department is now clouded.

Under D.C. police regulations, McClary cannot return to full duty as a detective in the robbery squad unless he can use his fingers to grip a gun - an officer must be able to shoot with both hands.

In addition, even if he did get back use of the fingers, McClary might still be kept off active duty. His commanding officer, Capt. Frederick Thomas, pointed out that under the current law, if McClary were to aggravate the injury in the line of duty he could ask to retire and would be entitled to 66 2/3 percent disability retirement pay.

But McClary does not want to be retired on disablitity. He wants to remain on the police force.

Although the retirement law is under review by Congress, it may not be changed in time to help McClary. As long as the "aggravation clause" remains, the department will not take a chance by returning him to street duty.

McClary is 27, and has been in the robbery squad since May 1976. Before that he worked undercover for four years in the Fourth District.

McClary, who has stylishly long brown hair and a quick smile, a boyish face and a mustache, likes police work, especially investigative work on the street. Now, he may never return to it.

"My doctor says that it's quite possible I'll never be able to use the fingers again," McClary said last week. "He thinks that at best something might be done in a year. But now now."

Since the accident, McClary has been assigned to "light duty" working in the robbery squad office, answering phones, writing reports - desk work.

An office can remain on light duty for six months. Then action must be taken. McClary has no idea what will happen when the six months is up.

"That's the hardest thing, just not knowing all of a sudden what your future is going to be, (at 40 percent of his current pay) they could mover me to another job or they could put me on sick leave. I don't know what they'll decide."

McClary was married last September. His wife Kathy, who has a five-year-old daughter by a previous marriage, works for a local real estate company. Between her job and McClary's pension ($7,400 annually) they could get by if he had to retire. But his concern has little to do with money.

"I just like being a cop," he said. "The years I spent in the fourth district were just great. We had a lot of good cases up there. In robbery you get interesting cases too. I like being an investigator."

McClary grew up in Hyattsville, and attended Bladensburg High School. During his first year at Prince George's Community College, his father had a heart attack and McClary dropped out of school to look for a job.

One day he walked by a police recruiting office in Washington, stopped and decided to take the test. Nineteen days later he was a police cadet.

"It's a shame when something like this happens, especially with Mike," Thomas said. "He's a good investigator, he works well without constant supervision and he's enthusiastic. That's what I like most about him, his enthusiasm."

"One thing I've not to do throughout this whole thing is feel sorry for myself," McClary said. "If you do that, well . ." he shrugged his shoulders.

"Sure, I think about it all the time." he said. "I think, why me? Why this way? It was such a fluke thing. I've played it over in my mid hundreds of times. So has my friend. We still can't figure why the thing bucked like that.

"In a way I was lucky because if the saw had caught me clean it would've sliced my hand in two. The doctors at the hospital did a gret job. I could have lost the fingers completely."

McClary tries to keep looking at the bright side - he took the recent promotional test fosergeant - but sometimes the five months of frustration show.

"I know in a lot of other jobs an injury like this wouldn't be that important, I could go on functioning. I'm 27, It's hard no knowing your future at this stage. I don't know what I would do if they retired me, I try not to think about it.

"I do know one thing though. Things aren't easy out there today. Jobs are hard to come by."

"I wouldn't have half the things I have right now if I hadn't become a policeman," McClary said with a slow shake of his head. "It's disturbing to have your whole life disrupted just all of a sudden.

"My wife worries about what's going to happen to me. So do I."