Radical extremist can not escape the long arm of the law. Once they are apprehended and taken to court, relevant laws will be applied to ensure they get justice that they deserve. Radicalization is criminal in nature though done in the name of religion, the law doesn't recognize or uphold killings in the name of god.
Yes, radical extremists that target gays will face the full extent of the law, at least in the United States. It does not matter under the law whether the victim of a crime is gay. The extremists who target gays will face the full extent of the law for the acts that they commit.
Especially following the outpouring of public opinion against the perpetrators of the recent violence and hate crime against the gay community, I think that it is reasonable to predict that anyone caught committing these crimes or similar ones in future will be subject to the absolute full measures of the law.
If the question here is if radical extremists will be prosecuted to the fullest extent based on if their targets are gay or not, I should certainly hope so! Any radical extremist should face the strictest punishment allowable and possible no matter who their target is. These sick individuals most be made examples of.