The IQ and psychological tests have been abandoned by the department that hired me after they were determined to be unreliable predictors of performance, and offensive to the sensibilities of desirable applicants. (I have diarrhea: A) Once a week; B)Once a month; C) Once a year; D) Never [actual question from the 'honesty index' test I took]
I was advised by the psychologist that I might be better off declining a cop's job: I was too creative, honest and intellegent. She said that ['big picture' capable] persons were prone to frustration and boredom-fatigue. I ignored her advice.
Hiring in the larger muni departments in my state is done exclusively by Civil Service test score, veteran status, monority status and lack of disqualifiers like felony conviction. Departments may or may not use additional tests like psychological surveys. But I don't think the latter could be legally used to discriminate. I think they were/are largely a research tool.