Do you think he's telling the truth about why he was arrested?

i was waiting down the street for my friend w/ benefits when i guess he got caught crossing the train tracks. the cops found me and called me over; they told me that he has "drugs" on him and that he's staying with them. they had him handcuffed and sitting on the ground so it seemed pretty serious to me. he told me later that night that he was just in trouble for crossing the tracks. do you think that's the truth? and why would he lie to me if he really did have drugs on him? thank you! we're both 16 by the way and we've been hooking up for 2 years.