Who dropped the ball here, the police or the hospital?

The police.

It is their job to escort suspects who need medical care to ensure they 1) don't escape and 2) don't hurt anyone. The ER staff can't be expected to know the status of patients with regard to law enforcement, nor do they have any authority to hold a patient against his will.

I say the law enforcement dropped the ball...
Check this line from the story:

I would insist that if you're under arrest that an officer should be there regardless...?

Local police stay until a patient is admitted, and then until a county sheriff takes over.
Suspects are often injured or develop chest pain after arrest.
Once I had to tell the sheriff to turn down the TV in the CCU. He had it loud so he didn't have to listen to the >75 year old patient he had handcuffed to the bed.
Later I found him asleep in our onlu cardiac chair.
I needed it for a patient and he became angry.
Actually asked, "Are you telling me what to do?"

Most are very considerate. He was an outlier.

The police should have stayed at the hospital with him. It is not my job an an ER nurse to "jail" someone in their hospital room (psych patients are another can of worms). We don't have tasers, guns, bars around the rooms, or the law behind us to do this to people under arrest.

On a semi-related now, it really, really angers me the way police give disorderly/drunk/obnoxious people the option of "going to jail or the hospital". Huh??? And which one do you think they choose? At least once a week I get a patient with a BS complaint who tell me the police told them to come to the ER or get arrested.

It doesn't say whether he was discharged, or just left AMA. If there were INSTRUCTIONS to notify the police if he was discharged, someone should have done that. I had a patient once with instructions to "notify TPD when pt is discharged." Since there was no number or name left, I called the "non-emergency" number in the phone book, and got "I have no idea what you're talking about." The arresting officer should leave a specific number, case number, badge number or whatever, and a BIG note if they want to be notified of anything. Otherwise, I don't have time to hunt someone down. And the police shouldn't ASSUME that the staff will notify anybody.

In my experience, unless the suspect has been arraigned (or actually charged with a crime), no officer will be there.

I would think that he left AMA since he was "last seen wearing a hospital gown". Unless he was arrested naked. LOL
In my part of the country, if someone is arrested, they have a guard on them from the police department at all times until they are discharged. Even if they said to contact them and left a good number when the pt is discharged, who is to say the patient won't leave AMA and just walk out before the police have time to get there? That is just ridiculous. It is NOT the hospital's responsibility. The police department dropped the ball!

In my neck of the woods, for a while, the police would say that they had been "temporarily" signed out of jail so that the county would not have to incur the cost of medical treatment. They would also try to get us to notify them upon release. Like prior posters, not my job to hunt down people to come take these folks! After a few "slipped through the cracks" that stopped! Our hospital requires that anyone arrested, regardless of status, has a guard in the room with them at all times for patient and employee safety. No if, ands, or buts!

Just my ignorant student nurse opinion, if the police wanted him they should have stayed at the hospital. I don't mean to be overly naive, but would calling the police at discharge violate the HIPPA?

I'm not going to try and make a violent non-psych patient hang around until the police try to arrest them. Sounds like something that definately isn't in my job description.

When we have Department of Corrections patients if one were to escape (hasn't happened yet) we aren't supposed to even approach them. If we see them we get the police.