Quite a few it seems - most outrageously committed in plain view, in open defiance of the laws that the system has, seemingly and reluctantly, finally enforced. From here:
Former Gatineau police officer Jeffrey Greetham, who was fired last February 9 after a disciplinary hearing, was formally charged Tuesday with sexual assault. [...] The crimes allegedly took place between 21 April and 1 May 2010 [...] In a terse statement, the Chief of Police of the City of Gatineau, Mario Harel, described the behaviour of the accused former police officer as "unacceptable". [...]More about Jeffrey Greetham, here.
During the years he was employed by the force, Greetham's record of charges for actions contrary to his professions code of ethics continued to mount, and in 2002, he had to answer two charges of sexual assaults against a 15 year old girl.
After a very brief hearing, the charges were dismissed. The judge concluded: "Faced with no evidence in support of the complainant's weak version of the alleged sexual assaults, the court is unable to discredit the accused's version."