A convicted killer in Utah today chose to be executed by firing squad, a method only rarely used in that state and banned almost everywhere else in the US.

Ronnie Lee Gardner, 49, murdered a lawyer and has been on death row for 25 years. He faces execution by five volunteers (who would be police officers) on June 18, having been given the choice of the firing squad or a lethal injection.

Utah joined the rest of the US in banning firing squads in 2004, mainly owing to embarrassment at the hordes of media which descended for earlier executions and portrayed the state's justice system as a relic of the wild west.

But Gardner is one of about 10 prisoners who were sentenced to death before the ban and so have to be offered the choice. Some of the others have also said they will opt for the firing squad.

The last person to be executed in this way in Utah was John Taylor in 1996. He said he had chosen it "to make a statement that Utah was sanctioning murder".

The only other state where firing squads are still permitted is Oklahoma, where the method is only for use in the event of failure of other means.

Gardner told the court: "I would like the firing squad, please." He made his choice after the judge, Robin Reese, told him that he had exhausted the appeals process and was unlikely to be given any further postponements. But Gardner's lawyer, Andrew Parnes, said he would appeal.

There is a commonly held belief that only one member of a firing squad has a live round and the others are given blanks, to help ease consciences at having fired a fatal shot. But in 1977 Mikal Gilmore claimed his executed brother Gary's shirt had four bullet holes in it.

• This article was amended on 27 April 2010. The original referred to Gary Gilmore's shirt having five bullet holes in it. This has been corrected.