For 22 years until she was slain, Stephanie Roper was a person--an infant, a girl, a young women and then, horribly, a murder victim. Now, though, she has become a movement--one that ill-becomes her life. There is the whiff of vigilantism to the Stephanie Roper Committee.

Last year, Roper had a car accident on a lonely Maryland road. It was three in the morning and two men stopped, saying they would help. Instead, they took her to an abandoned house, raped her repeatedly, beat her and finally killed her. The person convicted of doing the actual killing, Jack Ronald Jones, was given two concurrent--not consecutive--life sentences, one for rape, the other for murder. He will be eligible for parole in about 12 years.

A public outcry ensued. To some people, it seemed that Jones had gotten away almost scot-free. Instead of the death sentence for which he was eligible, the jury opted for life in prison. Instead of two terms of life in prison, the judge sentenced him to the equivalent of one.

Among those who felt that justice had been cheated were Roper's parents. They formed the Stephanie Roper Committee, which is now either a genuine political force in Maryland or an interest group with a real talent for public relations. It has held meetings and rallies, raised money and come up with a legislative agenda. Its substance is to make sure that no other killer ever gets such a light sentence.

The emotions behind the Roper Committee, especially when it comes to Vincent and Roberta Roper, are genuine enough. No one who has read their letter to the editor in The Washington Post could not be moved. They, like their daughter, are victims and they naturally seek something. But what? Justice? Revenge? From the legislation they propose, it's hard to tell.

And it may be asking too much of them to tell exactly what it is they want. But others, less emotionally involved, have a real obligation to be clear in their thinking. The sum and substance of the so-called Roper legislative package is to make it harder for a killer to escape execution or, if he does, to make certain that he spends a great deal more than 12 years in jail.

But Roper's killer probably will spend a great deal more time than that in jail. The mere fact that he is eligible for parole in 12 years does not mean that he will get it. He probably won't, but if he does it will be because the parole board thinks he is no longer a danger to society. Some people, after all, can be rehabilitated--not all people all of the time, but some people some of the time. Less than one percent of freed murderers kill again.

The Roper Committee has no patience with such arguments. Instead, it seems propelled by two thoughts--vengeance and the belief that harsh penalties are a deterrent. But in the Roper case, there is not the slightest reason to believe that her killers--the second man pleaded guilty to murder--ever considered what the penalty for their actions could be. It is not clear, in fact, if the pair, hopped up on drugs and booze, were in any condition to consider anything.

The state exacts punishment, not vengeance, and juries have an obligation to consider mitigating circumstances--drugs, booze--and not only the grief of the bereaved. As for vengeance, it is an understandable emotion, but it is not the same thing as punishment, which has a higher goal--deterrence and rehabilitation.

There is, in fact, no way to avenge the death of Stephanie Roper. There is no way to relieve her parents' pain, no way, death penalty or no death penalty, to stop these things from happening again and no way to second-guess a judge and a jury who had to consider matters other than vengeance.

There is a great deal of emotion bound up in the Stephanie Roper case--all of it understandable. It would be unfortunate, though, if all this emotion should be used to fuel a package of ill-conceived legislation. The bills substitute emotion for reason and that, after all, is what her killers did. The bills are no fitting memorial to her. She was better than her killers in life, and so should be a movement bearing her name.