not sure how things work between the UK and the US , we recently (last year) had the Entwistle case in Massachusetts (non death penalty State)
Entwistle murder case - Wikipedia, the free encyclopedia
I'm thinking from previous news reports the various States have to 'sign' an agreement with the extradition Country (if no death penalty exists) that it will not be carried out in the State where the trial is to be held . The one's which gets the most press are Mexico (non death penalty Country) , v Texas and California both border States , someone does a murder, jumps the border and is more or less free from extradition . Think Canada also follows a similar policy