Hello. What can be done to someone who committed arson 19 years ago? Yes, there are witnesses.

My uncle, who has done work as an electrician in the past, vowed that no one would spend another night in my grandmother's home. He hurried to the basement for a few minutes and then left the property. The next morning, smoke filled the house through the vents and everyone inside made it out but were displaced. Recently another family member came forward about knowing who was responsible for the fire. I googled the statute of limitations for arson and it hasn't been 20 years so we're hoping something can be done. Please help.