To call myself the greatest living expert on Homicide writing today may be an exaggeration; that I am that on Medium probably isn't. I think i've written anywhere between a dozen and fifteen articles dealing with it directly in the last three years and at last half a dozen indirectly. When the police procedural started taking heat in the last few years, I gave it another look. I think it holds up better than almost any other cops show in the last half century, at least in America.
Sadly Homicide is not on any of the streaming services in America (I don't know if it is in the UK.) i still have the entire series on DVD (it was one of the first TV shows in history to be released to DVD) . You might want to track down my articles to get a grasp of it: several I wrote this past year have to dow with many of the outstanding actors who had roles on it during its run. The most recent involve Melissa Leo and Giancarlo Esposito, who are two of the greatest character performers in history. Leo's career started on Homicide and it was Esposito's first role as a series regular.
I'm inclined to agree with you on One Hour Photo. That was a master class.