my friend is being arrested right now, HELP

One of my good friends just called me and asked if I was able to go out right now, unfortunately I am not. I asked why, and he said because he needs someone to pick up his car because he is being arrested. I don't know if I can call him back on his cell which he called me from, he didn't give me details, I DON't KNOW WHAT TO DO! P.S. He's probably being arrested for something weed related.