Updated

A former prison guard charged with killing two Tennessee postal workers had to be physically restrained and removed from a Memphis courtroom after an outburst during a federal court hearing.

Chastain Montgomery became upset Monday during his mother's testimony at a hearing to determine whether he is eligible for the death penalty if convicted in the October 2010 shootings of Paula Robinson and Judy Spray.

Montgomery has pleaded not guilty to charges including two counts of killing a federal employee while committing a robbery. No trial date has been set.

Defense attorney Michael Scholl said Montgomery was angry his mother was testifying at the hearing to determine if her son is intellectually disabled.

The U.S. Supreme Court and federal law have barred intellectually disabled people from being executed.