I agree with my colleague in that there is no single drug testing law or regulation in California applicable to all law enforcement agencies. I can't prove this negative, other than to say that I have looked through the various codes and I find no such law.
That said, California does have privacy laws which are much
more strict than those of any other U.S. jurisiction, which includes federal law.
The California Supreme Court has not yet directly ruled on the issue, however case law suggests that a drug test of an existing employee without any individualized suspicion is an "unreasonable search," unless the employee is in "a safety or security sensitive position." An employee's privacy interests may be outweighed by the employer's safety-related reasons for random drug testing its workers. This includes the employer's interest in reducing the risk of injury to coworkers. The employer's safety concerns may stem from the hazardous environment in which the employee works or from hazards inherent in the work itself. See Smith v. Fresno Irrig. Dist. (1999) 72 Cal.App.4th 147, 159, 84 Cal.Rptr.2d 775, 784.
Given that background, it is likely that random grug tests of law enforcement personnel is lawful, except perhaps for persons who are not directly employed in a safety or security position (administrative assistants, maintenance, etc.).
The California Police Chiefs Organization publishes a guideline concerning drug testing. See this link.
However, this guideline is not manadatory.
In the end, the drug testing of law enforcement officers in California is an issue determined individually by each agency.
Hope this helps.
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