SAN JOSE, Calif. (MCT) —The San Jose police officer whose 3-year-old son accidentally shot himself to death with a handgun he found in the family’s Gilroy home will not face criminal charges for leaving a loaded gun within reach of children, prosecutors announced Tuesday.

In an unsettling, six-page report that recounted for the first time what happened that day, District Attorney Jeff Rosen concluded that the tragedy was “a horrible, irreversible mistake.” But he found that it did not meet the required legal elements for charging Officer Brandon Orlando with either a felony or a misdemeanor for criminal storage of a firearm.