Does my son have to cooperate with police and go to court if he being accused of beating a man?

My son, 18, and his friends are being accused of beating a man up. According to the police, the man had to have screws put in jaw. At the night of incident, cops came to my house, put my son in cuffs and said that there were witnesses that were coming over to identify him. Witnesses could not ID him. They took my son, took cuffs off him and put him in the back of another cop car. They took him to the district to make a statement. A week or so later, detectives came to the house with mug shot photos for my son to ID. I told the detectives the night of incident that my son was drunk and smoked pot. The detectives said for my son not even try to go there that he is in for a penny in for a pound. He can't take back his statement and they know he was involved in the beating. If he doesn't cooperate, they will come after him.