IT is not, Louise Kelton readily admits, the first place you would expect to find a woman born in South Wales not far off 60 years ago: Washington, being formally sworn in as a US marshal, having been nominated for the post by President Barack Obama and duly confirmed by a full vote of the US Senate.

But that is where Kelton was last week. This week, she is getting down to work as the new US marshal for the Middle District of Tennessee. The legendary marshals are America’s oldest federal law enforcement office, charged with protecting the federal courts and their officers, transporting prisoners, serving arrest warrants and — most famously, as portrayed by John Wayne and Tommy Lee Jones in Hollywood movies such as True Grit and The Fugitive — with tracking down some of America’s most wanted fugitives.

“We go after the worst of the worst,” says Kelton, one of five women in the 94-strong service, and only the second black woman in its long and storied history. The task is not altogether unfamiliar; she spent 33 years with the Metro Nashville police department, rising through the ranks from patrol officer through sergeant, lieutenant, captain and finally commander of the city's North Precinct (“That was hard work; 16-hour days. I still get up at 3am most mornings”) before becoming deputy chief five years ago.

But it is all a long way from Tiger Bay, where Kelton grew up. She was born on a US air force base near Cardiff, the daughter of an American serviceman and a Welsh mother, and stayed there until 1978, when aged 23 she gave up her job as a hospital physiotherapist and took off to the States to see Louisiana, where her father came from. Running out of money in the capital of country music, she ended up being helped by an old friend of her mother’s. “I meant to stay for a year, but it didn't work out that way,” she says.

Kelton says she is “immensely proud and honoured” to be appointed marshal. She sees it as the culmination of a career spent “trying to make life better and safer and more secure for other people. I love people. That’s why I do this.” It was growing up in Tiger Bay, she says, that gave her the “confidence, independence and broad-mindedness” to get her where she is.

Her mother and brother, whom she last visited seven years ago, still live there. They’re proud of her too.

By arrangement with the Guardian