What I am not seeing is a license to operate, or filtering through a licensing process in the same way that it is applied to other professions where irresponsibility or negligence can cause significant damage to others. So long as he is not convicted of criminal charges an individual can get hired, fired and hired again by a neighboring agency on the same day.
I can't say that you are wrong in all jurisdictions, but I can say with complete confidence that you are utterly wrong with how that would go down in my town.
There is no independent review board that offers oversight or follow up on minimum standards of conduct or training that are required to work or continue working in that field. Generally speaking, a cop can't "lose his license" the same way a doctor can for misconduct, yet both can bring about your death.
First off, while it is outside of my realm of direct experience, I'm not so sure that doctors are such an awesome regulatory example to be emulated. Medical error kills a quarter million Americans a year and I'm relatively confident we aren't blackballing every single doctor who screws up and kills a patient. You are absolutely up in arms about cops who kill 1/250th of that number in a year - and most of them righteously. Very, very few docs can claim self-defense for their medical error kills. Maybe Millcreek can tell us a little bit about his experience with bad docs and medical error - I could be off base.
Regardless, can I tell you a little bit about how the police hiring practice actually works? I'm going to break this down specifically for the town I live in, since that is the only place I have direct, recent experience. I'm sure some departments are outliers in the process, but I can't imagine the one I happen to know about is drastically abnormal.
1. The Town Council approves the budget for hiring and the number of positions to fill.
2. The Chief advertises the positions.
3. Online pre-application
4. Physical tests (basic strength and agility)
5. Oral interview panel
6. Formal written application
7. Comprehensive background investigation conducted by detectives (criminal background check, interviews with previous employers, credit check, reference checks, etc).
8. Polygraph/Voice Stress Analysis interview
9. At several points along the way, candidates' records are brought to a Police Merit Commission on which I have served for the past six or seven months. This is a non-Law Enforcement oversight board who make all hiring, firing, and promotion determinations, as well as handling any serious discipline issues. The Chief asks the Commission to remove candidates who have failed at any step of the process. That could be based on physical performance, criminal history/admitted criminal behavior, financial red flags, or negative information provided by previous employers (including previous departments, if applicable).
10. For the given number of positions currently available, the Chief picks specific candidates and asks that they be certified by the Merit Commission. The Commission gets the whole file to review for each of the selected applicants. We're talking 3" binders full of documentation. If the Commission likes a candidate then they approve a conditional offer of employment and the applicant moves on to the next steps.
11. Medical evaluation
12. Psychiatric evaluation
13. Assuming they pass all the previous steps and do not yet have state certification they must attend the police academy Basic Peace Officer program, which is almost four months long.
14. 17 week Field Training program during which they operate under the direct instruction and observation of Field Training Officers.
If you already have a state LE certification you still have to undergo every step except the academy.
No, bad cops aren't going to be coming in from a neighboring agency and getting hired the same day. Or any day, so long as I'm on the commission. While I do get the appeal of a body that could yank credentialing from bad cops permanently and universally, I'm not convinced that it would necessarily be better or more effective to have a distant state or federal licensing board giving the thumbs up or thumbs down on officers. I'm not sure a Merit Board or Merit Commission satisfies your personal requirements for an "independent review board", but I feel confident in our department's process and the oversight that I'm a part of. We're preparing to start another hiring process soon. If you're interested I can give periodic notes on the process.
Also, contrary to kgbsquirrel's confidently ignorant assumptions, we do not have a ceiling on intelligence for applicants. Based on the criteria provided by an employment consulting firm we do drop a significant percentage of the the least qualified of applicants even if they achieve nominally passing scores, but there is no top end. Just like the DoD does, if they score too smart on our tests ... we hire them.