FRANCIS FORD COPPOLA WANTED MATT DILLON (DALLAS WINSTON) TO SPEND A NIGHT IN JAIL IN ORDER TO GET A BETTER IDEA OF WHAT HIS CHARACTER WAS GOING THROUGH.
Coppola wanted Matt Dillon (Dallas Winston) to really understand his character and really walk in his shoes to have a better understanding of what it is that he should be acting like for the actual scenes. So, Francis suggested that Matt spent a single night in a real prison surrounded by real delinquents and prisoners to really get a "ruffian sort of feel" from the experience. Of course, coming from Matt, it was a hard no.