Can I contact the victim and offer restitution before a case goes to trial?

My grandson works at valet parking and was arrested for allegedly stealing a $900 iPhone from one of the car. Victim traced phone to a local repair shop within the hour. My grandson signed a statement to investigator saying that he found the phone on floor and kept it. He also stated to the investigator that he sold the phone to a phone repair shop for $100. The store claimed to police that a man tried to sell the phone but they refused because the phone was locked and phone cannot be found. He was arrested and charged with dealing on stolen property and grand theft 3rd degree. He is out on $3000.00 bond and court hearing needs to be set.