In my jurisdiction (and probably everyone else's), officers frequently encounter the mentally ill. While many do not meet the criteria for an Emergency Evaluation Petition, some do, but agree to voluntarily accompany the officer to the hospital. This saves on law enforcement paperwork and gets the officer back in service faster. While those are good things, there are some negatives.
First is that the mentally ill subject can simply walk out the exit door if they haven't started the admission process. Secondly and more importantly for theirdiscussion, the legal paperwork for an EEP does not go forward. Certainly, not everyone who is depressed or anxious needs to be EEP'ed or lose their right to bear arms, but others need to be in the system, whether or not they voluntarily accompanied police to the hospital.
In my jurisdiction, while all officers, especially Crisis Intervention trained officers can write up EEP paperwork, the county crisis center and, I imagine, my former employer's mental health specialist have much greater expertise at field diagnosing severe mental illness and articulating the diagnosis for medical and judicial consumption. If you have a solid-performing mental health team as exists here (and I realize many do not), consider using them to get the severely mentally ill into treatment and the system.