So far this year, the city’s Office of Police Complaints has issued rulings on four cases of alleged police misconduct. In each case, the complaint czars ruled against the police. We’re running down the rulings, drawing what lessons they hold for working cops. The first was posted Wednesday. Here’s the second:

Summary of Complaint No. 05-0228: On April 5, 2005, a 15-year-old girl had been fighting with another student on school grounds. (The report does not disclose the school’s name.) An MPD officer detailed to the school assisted in breaking up the fight. The girl alleged that in the course of being arrested, the officer told her: “I’ll break your fucking arm.” She also alleged that the officer “grabbed her between her legs and slammed her to the ground while arresting her; picked her up by one handcuff, causing the cuff to cut into her skin; and repeatedly slammed her head into a metal doorknob, causing a laceration above her right eye.” She was later treated at Children’s Hospital for minor injuries, according to the report.

Date of Ruling: Feb. 23

Allegations Sustained: “Insulting, Demeaning, or Humiliating Language or Conduct”

Lesson: If you are going to beat on suspects, don’t warn them first.