SAN FRANCISCO (AP) — A California man imprisoned for 15 years in the death of his month-old son is free after prosecutors and a judge agreed that the scientific research underlying what was once called “shaken baby syndrome” has changed significantly in recent years.

Clifton Jones was released this month from Soledad State Prison after a judge agreed to resentence him to a lesser offense.

Jones was arrested the day after his son, Clifton Jones, Jr., died on Dec. 13, 2005. The 45-year-old says one of the first things he did after gaining his freedom on April 15 was to visit his child’s grave.