Roommate Threatening To Contaminate With My Food

Location: NYC.
Landlord has refused to help with the continuous and ongoing conflict between one of my roommates and the rest of us (3). He is continually creating issues over various things, most recently he has become upset at the number of crumbs on the counter and even went as far as to call a roommate meeting to show us 2 piles of crumbs- one of “acceptable” amount and one of “unacceptable” amount (they were virtually the same).

Things have recently escalated to my roommate threatening to contaminate my food and refusing to not touch my groceries. Is there anything I can do? I’m genuinely concerned and feel threatened due to how hostile and unpredictable his behavior is. He has no respect for others and has even blocked my other roommate from entering his room during a confrontation, and also put his hands on him (this is on video). As far as the food issues go, do I have any legal leg to stand on with either the landlord being negligent or criminal charges I can file? Currently planning to stop by my local precinct tomorrow to at least create some documentation in case things escalate.

Direct quotes from the messages:

“I have been patient with the island situation. This is unacceptable.
Next time I find crumbs on the counter y'all will be fishing it out of your food in the fridge.”

“I cannot maintain the social contract that we made promising not to touch each other's groceries”

“You cannot fail at a task dozens of times and then expect me to not retaliate”