In 1999, Cary Stayner murdered four people in the Yosemite National Park where he worked. This was a triple killing followed later in the year by the murder of a young woman he had almost certainly intended to rape. Whether or not there is any such animal as a usual serial killer, Stayner was unusual. (It is hardly worth arguing that he is not technically a serial killer because he murdered only on two occasions).
The unusual feature of this case was the arrest of two criminal lowlifes for the triple murder - one of whom confessed - and the extraordinary lengths to which Stayner went to throw the police off the scent. This is all the more curious in view of what happened when they pulled him in for the final murder, namely his prompt and unsolicited confession to the triple event. As far as the unusual goes, it might be added that Stayner's brother had been the victim of a predatory paedophile who kidnapped and held him captive for seven years. His brother died in 1989 aged only 24 following a road accident. It remains to be seen how if at all this affected Cary, but of course it in no way mitigates what he did.
At the time of writing, Stayner has not been executed in spite of being sentenced to death in 2002.