 The principal witness against him was his accomplice William Polwhele, who testified that Stanley and Jacques Fraunces had hired O'Collun, Annias and himself to kill the Queen.O'Collun was found guilty and sentenced to be hanged at Tyburn.He was executed, with Annias, the following July, by which time he was so ill with gaol fever that it was said to be hardly worth the trouble of hanging him at all.