Cops get faulty false confessions all the time.
Like this recent case. Man reports father missing, cops get false murder confession through psychological torture. Father turns up alive.
Judge rules officer questioning as ‘unconstitutional psychological torture’ and grants Thomas Perez Jr over £700,000 in compensation
www.telegraph.co.uk
I'm more familiar with the British system(s) but I expect details are similar in California/the USA. This case is some low-end banana republic stuff.
(1) Obviously most people know in this scenario you should get a solicitor/lawyer and either say nothing, or only what the solicitor/lawyer tells you to say. We don't even need any more information to see that Mr Perez was a vulnerable individual, being taken advantage of.
(2) Mr Perez was mentally ill and obviously distressed, and was not given a general medical check by a nurse, nor appropriate medical attention for his condition, despite begging for it.
(3) He was denied his medication, despite begging for it and suffering withdrawal symptoms.
(4) Mentally ill people are supposed to be accompanied by an 'appropriate adult' under these circumstances (relative/carer/mental health nurse etc.) There is a threshold of illness to be met for this to apply but clearly Mr Perez's condition passed it.
(5) If there's a question about whether the suspect may be too mentally ill to be criminally responsible he has to be assessed by a mental health expert.
(6) Mr Perez was read his rights for the first time in the mental hospital.
(7) They brought his dog into the interview room and threatened to have it put down.
(8) Mr Perez was told his father had been violently murdered although the police didn't know what, if anything, had happened to him.
(9) He attempted suicide while left alone in the interview room. Maybe this is what finally got him medical attention, in the form of being sectioned or in American English, 'taken to a hospital on an involuntary psychiatric hold.'
(10) You're not allowed to interrogate people for 17 hours straight. I haven't memorised the exact details but you have to have your basic rights explained to you when arrested [Edit: and 'checked in' at the police station] and get offered a booklet listing them. You can also ask for a big book with the word for word laws. If you have mental trouble of course someone can help explain it to you. You have to have eight hours sleep in 24, plus three meal breaks, plus drink and toilet breaks. They're not allowed to break up the sleep hours too much either. There are exceptions to all this kind of thing for some kind of extreme situation where say, the child you tied up in a cellar to ransom will die of rising flood waters in half an hour, and they need to ask you where the cellar is immediately, but they don't apply here.
(11) Mr Perez was held in a psychiatric facility in isolation for three days, believing his father had been violently murdered and his dog put down, although the police knew his father was ok, and the dog had not been put down. It's ambiguous whether 'isolation' means no contact with other patients, or visitors, or both. You're allowed personal visitors in psychiatric facilities, and advocates (trained person who helps you put your views across etc.), and usually a solicitor/lawyer. There are restrictions on time of day and stuff and people might not just be allowed access immediately but to be denied visitors sounds pretty unlawful.
(12) Mr Perez should have been handed over to medical staff within a short time of contact with the police, and there doesn't even seem to have been anything suggesting that a crime had been committed against his father. Nothing was mentioned in that regard in the material I've seen anyway. If I missed something with my limited time to look into this, or the laws are significantly different hopefully someone will pipe up.