3:04 PM PT -- Lyssa tells TMZ the cops were called over a fight she was having with her girlfriend. Lyssa says when officers arrived, she put her hand up in order to stop them from entering her room. Lyssa alleges the cop grabbed her by the arm and arrested her. She says she plans on filing a report for police misconduct against the officers.
As we've reported ... the Chapman family is going through some turmoil right now. Just months after the death of Dog's wife, Beth, he proposed to her best friend and maid of honor at their wedding, Moon Angell, on "The Dr. Oz Show."
Our sources say Dog and Beth's kids are hurt and pissed off, and even though the proposal hasn't led to an engagement ... they don't support what's going on and don't believe their mom would either.
Lyssa, specifically, fired off a couple vague tweets after news broke of Dog proposing to Moon ... seemingly trying to keep her cool about the situation.
Apparently, she couldn't do the same when she was getting arrested.