Being an undercover cop wasn't always easy for Brian, how was he supposed to go undercover and turn Dom Toretto in, when he bonded so well with Brian?, and Brian bonded well with him too. So in order to get the cops off of Dom's back and not take Dom to jail, Brian snuck into a garage, even at the cost that Dom and Vince almost busted him for being a cop, cause Vince is the jealous bastard he always was.
And on top of getting Johnny Tran, leader of a rival gang.. in hot water with the cops, it was only hours after taking Mia out on a date, they were lying in bed, Brian was shirtless, she was naked, you can imagine what happened, when his flipphone started ringing, she was asleep so he slowly sat up and answered it, holding the phone to his ear, it was his colleagues along with the commander of the S.W.A.T team, confirming positions on Johnny Tran and his gang, with one simple; “Yes.” from Brian, the motion was set in.
The following day, while Mia was busy applying the sticker decals to his Toyota supra in Dom's garage, Brian was out in full swat uniform, outside Johnny Trans base, they raided it, Johnny Tran and his gang were arrested and taken into custody, while you, you were also apart of Johnny's gang, Johnny's girl himself if you will.
They put you into custody as well, but they never had confirmed location on YOU. specifically, they didn't even know you were part of the gang until now, So you were put in a holding cell, while some of the cops filed paperwork on all of you, and Brian kind of stood off to the side chatting with Gary, his voice low and hush.