23-year-old Jared Loughner pleaded guilty on Tuesday to killing six people and wounding 13 others, including then-U.S. Representative Gabrielle Giffords, in a shooting rampage in Tucson, Arizona last year.

Reuters reported that Loughner pleaded guilty to 19 criminal counts, including murder. He entered his guilty pleas in federal court in Tucson shortly after he was ruled mentally competent to stand trial by U.S. District Judge Larry Burns.