A Texas inmate convicted of the death of a prison guard has been executed after the US Supreme Court rejected his lawyer's attempts to halt the punishment.
Robert Pruett was given a lethal injection yesterday evening for the December 1999 death of corrections officer Daniel Nagle at a prison southeast of San Antonio.
Mr Nagle was repeatedly stabbed with a tape-wrapped metal rod, though an autopsy showed he died from a heart attack that the assault caused.
Prosecutors have said the attack stemmed from a dispute over a peanut butter sandwich that Pruett wanted to take into a recreation yard against prison rules.
Mr Pruett's lawyers had previously convinced a judge that new DNA tests needed to be conducted on the steel rod used to stab 37-year-old Mr Nagle.
The new tests showed no DNA on the tape but uncovered DNA on the rod from an unknown female who authorities said likely handled the shank during the appeals process after the original tests in 2002.
Two appeals to the Supreme Court failed to halt his execution, however.
The 38-year-old Pruett was already serving a 99-year sentence for a neighbour's killing near Houston when he was convicted in Mr Nagle's death.
Pruett's execution is the sixth this year in Texas.