#1 Post his photo and crimes all over the net.
#2 Someone with courage will remove the gift of life.
Along with any freedom that they hold dear. Judges don't like vigilantes. They may do even more time than the perp.
Personally, have never understood why 'attempted murder' is not treated as seriously as is murder - particularly, when every measure taken to complete crime. Had this man not been interrupted; he would have strangled his victim to death. . .indeed a blessing for her and other victims 'are the brink'; but it should not be a curse nor a guarantee that another victim will take this victim's place. . .at some/any point in time.
Perhaps if this became a 'tourist alert' Justice would find this perp. . .