According to TMZ, Kase Smith, public information officer for the Houston police department, claims Peterson shoved an off-duty cop who was working as a bouncer in the club he visited last night. The officer/bouncer reportedly told Peterson it was time to leave and Peterson apparently ignored the instruction.
Smith says the officer had to come back and tell Peterson a second time that he needed to leave and Peterson shot back, "Hey man, we heard you the first time!" and pushed the officer in the back of his shoulder, causing him to stumble.
Smith says the officer then told Peterson to turn around and put his arms behind his back because he was under arrest and Peterson began yelling at the officer. Smith says the officer repeated himself and that's when Peterson turned around to face the officer and got in "an aggressive stance."
It allegedly took two more officers (three in total and at least two of whom were undercover) to arrest Peterson.
It is obviously worth noting that Peterson still does not appear to have been charged with anything—like, say, battery—except resisting arrest.
Update 5:06 p.m.: TMZ is also reporting that Peterson was "wasted" and trying to "intimidate" the staff. "[Night club general manager, Daniel] Maher says that once the officers subdued Peterson, the NFL star apologized for his behavior and told cops he doesn't usually drink. "