This is a good day for capital punishment anecdotes. Of course, most any day would work, given the number of martyrs over the years. If the pagans were not killing Christians for their faith, the Christians were killing each other over their heterodoxies (heresies).
But it's not the martyrs I want to focus on, but rather the attitudes of a couple of saints toward capital punishment. First up, St. Sigfrid.
Sigfrid was a priest from England who went to evangelize in Sweden. He successfully converted King Olaf, but while he was out preaching, his three nephews were beheaded by pagan raiders. The nephews, Winaman,Unaman, and Sunaman, all became saints in their own rights, not only because they were martyred but because their heads kept talking. Or at least that's the word that Sigfrid put about, which scared the piss out of the pagans. King Olaf decided that the raiders should be put to death, but Sigfrid asked that their lives be spared. Olaf then ordered that they pay a huge weregild, but Sigfrid declined the blood money, arguing instead that they be forgiven. His stock, and that of Christianity generally, went way, way up.
Angelus Scarpetti, on the other hand, was less successful in argument; he needed to make his point by more dramatic means. He contended that the life of a condemned man be spared, but the local authorities put him to death anyway. Angelus, a thirteenth century Augustinian friar, proceeded to resurrect the man. Take that, you Capital Punishers.