Crimianal background checks and drug screening tests, intelligence tests, personality tests, physical fitness tests
Yes. Police departments have Psychological screening tests that their applicants have to pass before they will hire them.
450 police departments
a
According to Wikipedia, there are 131 city police departments in Oregon.
There are a total of 141 police departments in the state of Florida. The largest of those is the Miami-Dade Police Department.
Police chief.
No. Many books and movies portray actual police departments.
courage
contrasting the roles and functions of municipal and county police departments
Most police departments do post job opportunities online. Job listings for police departments can typically be found on the city's website and include requirements of the position and instructions for how to apply.
More information about a police academy may be obtained by contacting local police departments. Local police departments will have information about training requirements.
Not all police departments are the same. Some departments let ranks as low as corporals become detectives, while some departments only allow lieutenants and captains. Regarding police, I have no idea what a "level" is