Meanwhile , Stella 's aggressive interrogation tactics with a witness threaten her police badge .
After examining the evidence in the murdered student 's apartment , the team finds traces of pure , unprocessed heroin and discovers that the victim had a female roommate who is now missing .
Stella 's aggressive interrogation tactics with a witness threaten her police badge .
After examining the evidence in the murdered student 's apartment , the team finds traces of pure , unprocessed heroin and discovers that the victim had a female roommate who is now missing .