Nothing in my post could be construed to imply that the US wanted him for murder.
Can he then be extradited back to Aruba to be tried and serve sentence for the first murder he committed before having to return to Peru to serve sentence on the last murder committed?
And we see your answer back ...
I'm guessing that Peruvian prosecutors will argue that both Aruba and the FBI had the opportunity to arrest him and convict him and they squandered their opportunities - and, as a result, he was walking around free to murder Miss Flores.
That's how one is able to ascertain what you're talking about ... :-)