Phillip Harkins, 38, has been battling against being returned to the US to face the charge since 2003 in what has been described as Britain’s longest-running extradition case.
The European Court of Human Rights in Strasbourg rejected his final appeal on Monday.
Harkins argued that being returned to the US would breach articles relating to inhuman or degrading treatment and the right to a fair trial under the European Convention of Human Rights.
If convicted in Florida he would face a mandatory sentence of life in prison without the possibility of parole, his lawyers argued.
Both complaints were declared inadmissible and the court said its decision was final.
Harkins, who is originally from Greenock, Inverclyde, was indicted for murder after Joshua Hayes was killed by a gunshot wound to the head.
The incident happened during a robbery in Jacksonville, Florida, in 1999.
Harkins insisted he had no involvement and has been contesting his extradition since March 2003.
He was released on bail and returned to Scotland in 2002 but was jailed in 2003 after being convicted of killing a woman in a road crash in Greenock.
Harkins lost a number of attempts to stop his extradition but took his case to the European Court of Human Rights where his initial appeal was rejected in 2012.
Despite a petition for a final hearing, the court ruled the complaints should be declared inadmissible as they were “substantially the same” as those considered in 2012.