I've read that France will not extradite a French citizen. So that's one other place to hide, if you're a French citizen. You won't escape justice that way, I think - if necessary they'll try you in France for a murder you committed in the US - but you'll escape US justice.
Article 3(1) declares that neither State has an obligation to extradite its own nationals, but the executive authority of the United States shall have the discretion to do so. The nationality of the person sought shall be the nationality of the person at the time the offense was committed.
Article 3(2) requires a State that refuses an extradition request solely on the basis of the nationality of the person sought to submit the case to its authorities for prosecution, if so requested by the Requesting State.
However, France is also subject to the European Arrest Warrant, which means they are "precluded from refusing the surrender of their own nationals wanted for the purposes of prosecution, but they may condition the surrender of a requested person on his or her being returned to the issuing state to serve any sentence ultimately imposed". This is obviously only for other European countries, but I bet you could then extradite from such a country to extra-EU jurisdictions simply with political help.
So let's say person X is wanted in the US. They get Country A to emit a warrant for them, A gets X from France, then extradites X to the US.