A Missouri inmate was put to death on Tuesday for a 2003 killing in what is believed to be the first execution of a transgender person in the United States.

Amber McLaughlin, 49, was convicted of stalking and killing a former girlfriend, then dumping the body near the Mississippi River in St Louis.

McLaughlin’s fate was sealed earlier on Tuesday when Republican Governor Mike Parson declined a clemency request.

McLaughlin spoke with a spiritual adviser at her side as the fatal dose of pentobarbital was injected. She was pronounced dead a few minutes later,

In a final written statement, McLaughlin regretted her actions. “I am sorry for what I did,” she said. “I am a loving and caring person.”

A database on the website for the anti-execution Death Penalty Information Center shows that 1,558 people have been executed since the death penalty was reinstated in the mid-1970s.

All but 17 of those put to death were men. The centre said there are no known previous cases of an openly transgender inmate being executed.