re: WTF do the police and EMTs do here?

40 years ago she would've been warehoused in an insane asylum until she died. Today, she will be "treated", eventually harm someone or herself, be a complete burden to society and its resources, and then die. At which time a social worker or family member will say "but she was fine when she was on her meds"

Regardless, I would start with a fire hose and bleach and work my up from there.