THE WA Police Union says it is concerned by the increasing number of detective vacancies and the rising rate of crime.
President George Tilbury said he feared the positions would not be filled for several months.
WA Police has advertised nearly 50 detective vacancies.
The Midland office has four vacant positions and Mundaring and Forrestfield are both one down.
Midland, Joondalup, Mirrabooka and Rockingham police stations were all down four detectives each and Perth is missing seven detectives.
Other suburbs are worse off in police department summary statistics.
Armadale and Kensington are each five detectives short.
Police Minister Liza Harvey said the positions had been advertised and would hopefully be filled soon.
“We have been telling WA Police until we are blue in the face that the detective vacancy issue is a serious problem and that changes need to be made to ensure the positions are filled by suitably qualified police officers,” Mr Tilbury said.
“It concerns me that the last three detective training schools have not been filled. It is clear to the union that had these schools been filled then the vacancy issue would be slightly better, but there are still issues which are preventing officers returning to detective positions.
“Our members are telling us that due to crime car duties and relieving at district control centres they are getting taken away from their crime files so often that they are unable to complete investigations in a timely manner.
“This has a direct impact on the community as the public expects police officers to complete their files but it is near on impossible to work on investigations while you are regularly spending time patrolling the streets in a crime car.”
A Police Minister spokesman said the matters were operational and therefore questions should be directed to the WA Police Department.
“The Government provides police with the resources to do its job, including recruiting an extra 550 extra officers which it is on track to do,” he said.
Opposition police spokeswoman Michelle Roberts said Ms Harvey had failed to protect the community with increasing crime rates due to the detective shortage.
“Additionally they are getting called off to do other general duties, causing frustration for the victims of crime and the detectives as well,” Ms Roberts said.
“The August crime stats show the biggest increase in crime in July this year compared to August last year. Catching criminals is the biggest part of the equation, not less resourcing in the stations.
“It’s no wonder crime in Perth is rising and offenders are going unpunished with our police under such extreme workloads.
“As a former Police Minister I’ve never known the vacancy rate for detectives to blow out by so much.
“In the Gallop Government the highest vacancy rate across the State was five.
“Detectives are the police who go out and investigate crimes and track down the offenders.”