Most important line from the chapter and why

The most important line from this chapter chapter 9 is when Julio is about to tell they something that could change the whole case this in my opinion was the most engaging part of the book so far.
So Julio knows someone who might be a witness to the prosticutioners side of the case and there have been no witnesses to the crime so far from that side of the case yet so this was a very important part of the book
"Well my cousin was sitting under some trees eating lunch kind of hiding because his lunch break is the only time he gets to be alone and he saw a man in a golf cart going really fast down the path along the fairway the man had a set of golf clubs on the bak of his golf cart but he was not hitting balls he was in a hurry suddenly he veered to his left and parked the cart near the patio of the house where the lady was murdered and went inside and then not long after the man came back out and went speeding off back to play golf."
Then it goes on to tell you that the cousin saw mr Duffey the suspect of the case on the news and said that was the man he saw. So the only thing stopping them going to the police with the witness is that the witness is an illegal immigrant and he has a family to support and he can't afford to be deported.