An internal study of the Montgomery County detective bureau has questioned the competence of the detectives who handle the county's ever increasing number of burglaries.

The report, which evaluated the crimes against property division, found that the detectives, after making an arrest in a single burglary case, often closed the investigation on several other cases as well simply because the burglaries happened to occur in the same geographical location.

In addition, the report states that the detectives claim credit in their departmental statistics for solving cases that some other unit worked on - notably, the uniformed patrol officer.

Quite frequently, the detectives were unable to recover stolen property in the cases that they reported were closed, the audit revealed.

The primary function of the crimes against property division is to do follow-up investigation on burglaraies and larcenies, once these crimes are reported to police. The unit also is responsible for making any arrests in connection with these crimes, for recovering stolen property and for gathering the evidence against a suspect to be presented in court.

During June 1977 while the division was under study, the detectives reported closing the investigations on 149 cases. But in 47 of those cases, according to the report, uniform crime reporting standards were not met - that is, the detectives made no arrest and did not have enough evidence on a suspect to make an arrest. There were approximately 5,600 house and commercial burglaries in the county last year.Police estimate that one of every 50 homes in the county eventually will be burglarized.

Major Wayne Brown, chief of the department's investigative services, said that it is common practice for detectives to drive to a particular neighborhood with a burglary suspect in an effort to get the suspect to point out homes where he has committed other burglaries.

Brown acknowledged that the suspect is generally granted immunity from prosecution in the additional burglaries. However, in this manner, the detective bureau is able to close a variety of unsolved cases.

In one particular case, Brown pointed out, a suspect was arrested and charged in two burglary cases and indicted on 33 other cases. But police believe that he was responsible for 60 additional burglaries because the same method of operation was used in those burglaries and they all occurred in the same general area as those burglaries for which the suspect was originally charged.

Police thus felt justified closing those 60 additional cases, Brown said.

Brown denied that the property division was closing cases that did not meet uniform crime reporting standards.He said that although some cases are recorded as closed within the department when they are reported to the FBI, which keeps official crime statistics, they are reported as "open" or unsolved.

He also denied that his detectives were taking credit for cases investigated and closed by patrol officers. Brown said that even if a detective merely participates in a case by placing one phone call or giving advice to the investigating patrol officer he has in some way contributed to the investigation.

Captain C.R. Perry, a former detective who participated in the audit said,"What's important is that (the department) is objectively looking at our own shortcomings and trying to find way of improvement."

Under the direction of Police Chief RObert J. diGrazia the department's management, audit and evaluation division has been studying the efficiency of several of the units with in the department.

Di Grazia is vacationing and was unavailable for comment. HIs chief administrative assistant, Philip H. Marks, said the report "is in line with national studies done recently on detective work... They bring into question how valuable the investigators' work is compared to what the patrol officer has been doing," Marks said.

He added that the county police are conducting an experimental program called Managing Criminal Investigations (MCI), which only are pursued where there is enough evidence that the case is likely to be solved.