I've had a couple of experiences personal and professional and I'm a bit 50/50 to be totally honest where the police and MH is concerened.
Personally speaking when I took and overdose and headed for the local cliffs in minus weather conditions and very little clothing I actually found them firm but fair. I was found by a member of the lifeboat crew who had been scrambled - on his way to the station he somehow managed to see me on the side of the road, on a grass verge, on an unlit road - and before passing out I had deliberately tried to crawl as far away from the road as I could. Even he said that he didn't know what made him look right there right then. Anyway I digress, the police were out looking for me on foot, in patrol cars, the dog section were called and the helicopter was out. When the lifeboat man (who by some stroke of luck was an RMN by day) alerted the police they arrived with an ambulance. I can't remember a lot I was in and out but I do remember, after being put into the ambulance, a police officer came up to me and asked me some questions, I couldn't really answer him but he asked my permission to turn me over to check the tattoo on my shoulder to ID me. He was straight to the point but not abrupt. When I was in A & E I came round a bit and in that post attempt self loathing I refused all treatment. A police sergeant came to talk to me with the Dr and told me again straight to the point but not unkindly, that if I didn't accept treatment I would be sectioned there and then and have no choice. He gave me half an hour to decide whether I was going to comply with them and allow medical treatment and following that, voluntary admission to the psychiatric unit. He said if I didn't agree, or tried to do a runner that I would be sectioned immediately. I agreed. He may of had some training or experience because my mother was there giving me the old "Look at all the money and resources you've wasted blah blah blah" and he turned to her and said that he hardly considered saving the life of a young woman to be a waste of anybody's resources, he said that himself and his team were in that job to help people and that he felt that they'd done their job by finding me and getting me to help. I found that touching considering that I felt totally worthless right then.
However I also worked wit EMI (elderly mentally ill) patients for a time we had illnesses ranging from Alzheimers and dementia to those who had suffered life long with bi polar, depression etc but who no longer had family to care for them or had come out of units at 65. When we needed hospital transfers, depending on the patient a member of staff would accompany the patient and sometimes a police escort would follow the ambulance. One patient I accompanied was treated very badly, they were actually trying to protect me from the threat that they perceived from the ambulance crew and became violent, the police forcibly restrained the person and removed me from the ambulance, I could hear them shouting that they would section them etc, this patient had absolutely no capacity to understand that. They wouldn't let me try and talk to them, or listen when I tried to explain why it was happening. I was there to escort the patient and to provide support yet when needed most I was removed and ignored. It put myself and the patient under unessential stress. This patient had a behavior cycle of 'protecting' young women who they considered were under threat from men, both ambulance crew were men, both police officers were men. We had dealt with this before on our unit and never had to restrain - rather talk the person round. This patient was being transferred for a medical condition and that condition, in my opinion (which might not be much I know) was considerably worsened by that incident. They never came out of hospital.
Ultimately I think the police are like all walks off life where MH is concerned - some understand and some don't, and it's the luck of the draw.:sparkle: