How much time is he looking at for an empty bag that had traces of Meth found in his room?

What is he facing for marijuana cultivation? Three months ago, cops show up at the mom’s house of my baby’s father where he resides. They told her (his mom) someone called the police department. She let them in the house. They went to his room, searched it, found an empty bag that tested positive for meth. He said it was from years ago. Upon searching, they noticed on his headboard there was a grenade. He told the cops it belonged to his dad and they took it. His mom told them his dad has had it since 1960 in the house and kids at one time played with it outside as a toy with their G.I. Joe dolls. They found a plant growing in the back yard. They haul him off, question him we live in a small town and after a few hours, they released him. This happened back in October 2012. Now on November 22, 2012, they show up at his mom's house with three warrants for possession of meth, possession of unlawful firearm and intent to grow marijuana. He is out on bail now. He was in the military and had a dishonorable discharge about 30 years ago. He also has been on probation in the past for assault family violence and possession of marijuana. He completed his probation with no problems and paid all his fines. What should he do? When they picked him up in November 22, 2012, they took him to our local small police department before taking him to the county while in custody here in our small town. He signed a statement saying he had the grenade and that it was his dad’s, he had it on the headboard where his son sleeps when at his home and he signed it. He also is a MHMR patient on meds for depression. He shot himself in the head about 10 years ago, which left him slow and like a teenager not realizing right from wrong at time. He lives on disability in his mom’s home and she pretty much supports his needs and habits.