Twenty PCSOs were sacked by the Metropolitan Police in 2008
Boredom and a lack of motivation is causing some police community support officers (PCSOs) in London to commit criminal offences, a report has said.
PCSOs were responsible for most cases of gross misconduct among Metropolitan Police staff in 2008, despite making up only 20% of the workforce.
Some felt akin to "glorified security guards", the force's HR director said.
The role was created to put more uniformed police on streets and to take some duties away from other officers.
The Police Federation has described the introduction of PCSOs as "policing on the cheap", while other critics have expressed concern that PCSOs have no power to arrest suspected criminals.
Senior officers at Scotland Yard are to review the role of civilians in PCSO positions as a result of the report.
In more than half of the 35 cases of gross misconduct against PCSOs in the Met in 2008, employees were sacked or reprimanded for offences such as drinking and driving or other motoring crimes.
On other occasions, police computers were misused or there was inappropriate behaviour, while in one case, a false allegation was made by a PCSO.
In all, 20 PCSOs were sacked, while there were formal reprimands for the other 15.
The role of PCSOs is to be reviewed in the wake of the report's findings
Another 20 cases of less serious misconduct were recorded.
Some PCSOs felt the scope of their roles was severely limited and they were not able to use all of their skills and experience as a result, said Martin Tiplady, the director of human resources at Scotland Yard.
"This led to feelings of boredom, reduced motivation and increased discipline activity," he added.
And there was a damaging "us and them" culture within the force between sworn-in officers and PCSOs, Mr Tiplady said in his report.
Making recommendations about how the situation could be improved in future, he added: "Instances of discipline are less likely to be committed where there are mixed teams, strong consistent supervision, a variety of work and, crucially, where individuals and teams understand how they contribute to effective policing."
The force's watchdog, the Metropolitan Police Authority, is due to discuss the findings at a meeting on Thursday afternoon.