A 12-person Umatilla County jury returned a guilty verdict Thursday for Alan Arthur Watkins, a 26-year-old prison inmate who assaulted and attempted to kill Correctional Officer James Hinkle in 2005 at Eastern Oregon Correctional Institution.

The jury deliberated for less than an hour before it found Watkins guilty on six counts of attempted aggravated murder, seven counts of assault in the second degree, seven counts of assault of a public safety officer and related weapons charges.

According to a news release from the office of Umatilla County District Attorney Dean Gushwa, attempted aggravated murder is a Measure 11 crime and carries a 10-year minimum mandatory prison sentence.

Judge Daniel Hill is set to sentence Watkins at 9 a.m. March 14 in the Umatilla County Circuit Courtroom No. 3.

Gushwa said his office won’t release further information until sentencing.

On Aug. 25, 2005, Hinkle was on duty inside one of the prison’s housing units when Watkins launched his attack. Watkins allegedly used a piece of metal broken off a shelf bracket and fashioned it into a knife that he used to stab Hinkle multiple times.

At about 8:30 a.m. that morning Pendleton Ambulance transported Hinkle to St. Anthony Hospital, where doctors treated and released him.

Oregon State Police detectives investigated the incident with assistance from the Oregon State Police Forensic Laboratory and Department of Corrections personnel.

Watkins killed his former foster mother in 1997 in Corvallis. He has been serving a life sentence for aggravated murder for the crime since then. Watkins was 14 years old when he killed her.

Hinkle started his career at EOCI in November of 1994.