ETA: As for Flack, he could have gone through his police training just after highschool, which assuming hes about 30 - 35 would have been sometime in the early 90's (give or take) and god knows how frequently course requirements fluctuate. Requirements gets stricter and stricter the more crime itself advances in a society. In the 70's there was no such thing as internet crime, therefore there would have been no investigative branch dedicated to that kind of criminal activity and regular officers would not have been trained how to deal with such instances. As long as how we commit crimes is going to change, what officers are going to have to be trained in is going to fluctuate. Even in the 90's DNA was still fairly new, being that we hadn't developed the first DNA profiling test until 84 and still hadn't been used to effectively solve a crime until 86. But again, state and municipal guidelines are different all over.
That line about Flack only having a high school diploma always bugged me. It was an unnecessary put down to Flack. I don't know how things work in NYC, but at one time it was usual for people to go straight from high school to the Police Academy. Although, at least in large cities, it is becoming harder and harder to make detective grade without a university degree in criminology. However, Flack appears to be doing well in his career.
Someone mentioned that Stella had worked narcotics. In Hung out to Dry, didn't Danny say that he worked narcotics as well? He recognized the image of Hypnos because he busted a dealer who had used it.
I think with Hawkes, it's different. He may not be the ME anymore, however, he still has his doctorate, which is something that is impossible to take away from you. Yeah, your licenses to perform surgery/do autopsies can expire, but your doctorate, once you become an MD or PhD, cannot be taken from you.
A license can be stripped for malpractice, but a PhD cannot, except for extreme academic dishonesty, IIRC.
Ummm. I'm going to split a hair with you on this one. I believe that Hawkes is called Doctor because of his status as an MD, not because he holds a PhD. He may or may not be a PhD as well, but I don't believe that we've ever learned that in the show. Although, he has been referenced as a genius at times.
However, we do know Hawkes spent 5 years working the ER and was also licensed to perform surgery. All prior to becoming an ME. As far as we know, he is still a licensed MD.
Generally, whenever someone holds the title of Doctor (either an MD or PhD) it is used in conjunction with any other title(s) they hold as a courtesy. Let's face it, both are damn hard to get, so who would want to give up the recognition?