A serial killer who preyed on older gay men during a rampage 25 years ago around the East Coast of the US has been executed.

Gary Ray Bowles, 57, was pronounced dead on Thursday evening after receiving a lethal injection at Florida State Prison in Starke.

He was condemned to die for the 1994 murder of Walter Hinton in Jacksonville Beach.

Mr Hinton was Bowles' sixth victim in the eight month killing spree that began in Daytona Beach with the slaying of John Hardy Roberts.

In between, there were victims in Maryland, Georgia and Florida.

In each case, Bowles stuffed the victims' throats with objects: towels, rags, toilet paper, dirt, leaves and even a sex toy.

"He probably enjoyed it after a while," said Thomas Youngman, a Daytona Beach detective assigned to the Roberts murder.

"Why do you kill people after the first one? The first one could be a mistake, maybe. But then the second, all right, I'll maybe give you that. But the third, fourth fifth and sixth? When do you stop?"

It was not hard for Daytona Beach police to figure out who killed Roberts, the first victim in March 1994.

Bowles left a probation document at the scene and also was caught on a cash machine camera trying to withdraw money from Roberts' account.

What proved more difficult was capturing him, something they were unable to do until after five other men in three states had been slain.