I have a little story from a male, European perspective that while not nearly as awful as your stories, also illustrates how little police care.
When I was 16 I got into a fight with an older lad. In all honesty, I should never have agreed to fight, I was smaller, weaker and not nearly as rough as him but hey, I'm an idiot so we went at it. Suffice to say I got my arse beaten. My nose was halfway across my face , my eye was swollen out like a tennis ball and I was covered in my own blood. Fairs fair, I put myself in the situation and had to take my licks. As I was making my way home after, I happened to pass by a police officer. It was early afternoon and summer, so full light out. There was no way he didn't see me so I prepared myself for what bullshit answers I would give when he stopped me. He didn't, however. He walked right passed me. He looked me in the eyes and then turned his head away and kept walking. Maybe he thoought by the way I was dressed that I was just some scumbag who wasn't worth helping. Maybe he had heard that there was a fight in the area and he thought he was doing me a favour by not causing me the hassle of having to explain myself. Either way, I've never understood how, as a police officer, he could walk past a fairly young looking 16 year old boy with a broken, bloody face and not even break his stride.