Credit card fraud? Please help!?

I just asked this question but I still have a few more questions. Ok so my brother stole my paps social security number and opened a credit card and also a po box (in my brothers name) to get all the mail.. And he charged around 240$ maybe a little less and tried to make a big purchase and they turned it to the fraud dep. He then called the company and acted like my pap and told them to close the account and he would send a check. He is afraid they will be able to find him by his bank? So can he send a money order and pay it off so my pap doesnt find out? If he does send a money order will they still contact my pap? My bro also put his own cell number for the main phone number? Also can my pap find out it was him? If so will the police locate him and arrest him even though this is his first time ever doing anything bad? Will americAn express even investigate this since it's only around 240$. And if he does pay it off how can he get the exact balance to put on the money order? He turned down the wrong road and realized and I want to get him help, but first I'm scared for all of this. Thank you