Deranged Grandson And Squatter Rights

Hello everyone, i have a current situation i absolutely need some help navigating before consulting a lawyer

i will begin by saying this is all taking place in the US in the state of VA.

my grandmother is currently allowing my cousin (her grandson) to stay at her house. there is no lease, but he has been there for 30+ days. we are attempting to get him removed from her house, a small part of the battle is getting my grandmother to engage with the police on the eviction process

my cousin and her grandson is

1. On the SO registry for molesting his own daughters
2. has some form of mental issues, probably due to prolonged meth usage

he is not in reality right now. he thinks AI is coming to get him, he is fighting AI generated people in the back yard, he’s showing overly aggressive tendencies toward even my sweet grandmother.

i am currently terrified for her life. we had gotten him into a mental health facility a few weeks ago, they released him after 8 days, they have now placed him BACK into another one, hopefully for a longer period of time.

now to my legal question - are we able to evict someone who is NOT under a lease while they are in the mental hospital? this man is 100% a threat to my 80 something year old grandma, and the quicker i can get her to file an eviction is the less overlap we have between him returning from the mental hospital and his set eviction date.

thank you in advance. any advice on evictions on people in mental institutions in the state of VA would be VERY appreciated by my entire family.