A convicted killer serving a life sentence at Scotland Correctional Institute was treated for stab wounds after an assault earlier this week.

Mario Ivan Martinez, 29, of St. Pauls, was stabbed in the back with a screw driver on Tuesday by "an acquaintance," according to a sheriff's report.

The report did not name the assailant or list if it was another inmate.

Video footage of the incident was taken into evidence as was the red-handled screwdriver used in the attack, the report said.

The deputy investigating the case could not be reached for comment on Thursday.

Martinez was convicted of first-degree murder in the 2006 shooting death of 20-year-old Christopher Emanuel of Shannon, N.C.

Investigators believe Martinez picked Emanuel up from his home and took him to an abandoned mobile home, where he beat the man before shooting him several times. He then dumped the body in a field less than a mile from his home on Shannon Road.

After the killing, Martinez fled to Houston where he was apprehended by Texas Rangers and U.S. Marshals.

Martinez was convicted May 6, 2010 and has been in prison since.

The state Department of Correction lists Martinez as being in closed custody on administrative segregation.

Scotland Correctional is a 1,000-cell, high security prison on McGirts Bridge Road near the Scotland-Robeson County line.

The prison is less than 20 miles from where Emanuel was killed.