What do I do if someone has drugs and a gun in my car and said that it is not theirs to the police?

I picked up someone I thought was a friend. He had a gun and drugs and we got pulled. The police pull us over, ask to search the car and found drugs and a gun. He said it was not his and now we both have the cases. I have no record after 28 and would like to keep it this way. Please help!