For the criminal who robbed a store burglarized a business establishment or committed an assault in the District in 1973 the chances were only five out of 100 that he would be convicted of his crime and only about two out of 100 that he would be sent to jail for it, according to a new criminal justice study released yesterday.

The study is based on a unique new approach that estimates the number of crimes actually committed, compares it with the number of crimes reported to the police, and then tracks the cases through arrest and conviction.

Instead of focusing solely on the conviction rate as announced by prosecutors or arrest rates as announced by police, the study provides what it calls a "systemwide perspective" from the point of view of the victims, or "consumers" of crime.

According to the group that prepared the report, it raises serious questions as to whether citizens are reporting crime, police are making enough arrest, prosecutors are convicting enough defenders, witnesses are cooperating fully with law enforcement officials, and whether judges are sending enough defendants to jail.

The study was prepared by the Institute for Law and Social Research, a Law Enforcement Assistance Administration-funded project that provides computer assistance for criminal justice systems in various cities across the country. In addition, to the criminal "consumer" study released yesterday, INSLAW also released the following two complete or partial findings in other statistical areas:

A study of the U.S. attorney's office here in 1973, which indicated prosecutors work hardest on the cases in which they feel they can win a conviction, while other cases - even those involving a more serious defendant - receive less attention.

Critical portions of the study were strongly contested by U.S. Attorney Earl J. Silbert.

The study also makes it clear that the new Operation Doorstop, a program startedhere last fall in which police and prosecutors are focusing on repeat offenders, "deals more effectively with this problem.

A partially completed study of police performance in the District in 1974, which shows that about 10 per cent of the police force accounted for more than half of all arrests. INSLAW also founded that, even subtracting the number of the police officers who made no arrests at all because of their work assignments, a small number of officers made a disproportionately large volume of arrests.

The study also shows that the police officers who made the most arrests also were more likely to have their arrests stand up in court.It said research is continuing to identify the characteristics of such highly productive officers.

One characteristic has been isolated, however. The study shows that an officer who lives outside the District makes more arrests and is more likely to have his arrests stand up in court than officers who live inside the District - even after accounting for differences in experience and other factors. The study does not explain this phenomenan.

Since various cities, including the District, are considering regulations to require police officers to live within the jurisdiction where they work, the study said its finding "suggests that local government officials should carefully weigh the tradeoffs involved" when considering such requirements.

But the major criminal justice system study released yesterday was the so-called "consumer" study, which INSLAW said represents "the bottom line for system performance, especially from the perspective of the citizens - potential victims all - who are the consumers of criminal justice."

The study deals with the three specific crimes of "commerical robbery," "commerical burglary," and "aggravated assault." In an attempt to get the systemwide overview sought by the study, it begins with the number of convictions for a particular type of crime and traces back to the number of such crimes actually committed.

For example, in the crime of commerical robbery, the figures showed that in 1973:

Eighty-nine of the 94 persons indicted on these crimes were convicted, a 95 per cent figure that prosecutors could point to with pride.

However, by going back another step or two, it can be determined that prosecutors, because of various evidentiary problems, dismissed about half the cases they had accepted from the police.

The police, meanwhile, had only made 177 arrests for the 2,070 reported commercial robberies - crimes that depend largely on witness identification under trying, fleeting circumstances for successful apprehension.

Based on a survye, another 300 or so commercial robberies were not even reported to police for various reasons.

Thus, only 81 persons went to jail for the 2,300 commercial robberies - or a figure of 3.5 per cent - that were committed that year the study concludes.

The study suggests that the police, therefore, should spend more time educating businessman as to crime prevention methods and take other crime prevention steps instead attempting to increase arrest rates.

In the field of commercial burglaries, even a smaller percentage of persons went to jail when compared with the estimated number of those crimes committed the same year, according to the study. It shows that only 43 persons went to jail for the 8,600 estimated burglaries, or a figure of one-half of one per cent.

The study showed also that only about half those crimes were reported to the police, and that the police had a low arrest rate for those that were reported.

The prosecutors, however, has a conviction rate 86 per cent for the cases they ultimately accepted and indicted.

In aggravated assault cases, about one-half of the crimes were never reported. Of the 3,600 that were reported, police arrested 1,900 persons.

Prosecutors, however, ultimately indicted only 286 of those persons - with most of the cases dropping out of the system because of witness problems along the way.

Prosecutors said, for example, that many assault cases involve persons who know each other and who may fail to press charges once their tempers have cooled. Many other cases are dropped because victims fail to make an adequate identification of their attacker and the prosecutors do not feel the case will pass muster in court, they added.

Only 116 persons went to jail for aggravated assault convictions in 1973, compared to an estimated 6,900 attacks - a conviction rate of less than 2 per cent.

U.S. Attorney Silbert said in an interview that he considers that 1973 statistics "alarming," but said that in many ways they merely corroborate various practical findings that the prosecutors had seen through their experience here.

"Some cases always will be dropped," he said, "because the prosecution standard is different from the police standard." For example, a policeman may have clear cause to make an arrest in an assault case and witnesses may later decline to press charges, he said.

Silbert was more concerned about the number of crimes that were committed but not reported by citizens.

"The key for successful arrest and prosecution of street crimes is that availability of witnesses," he said. "The police and prosecutors have a responsibility to be accessible, and citizens have to be willing to come forward."