In the second half of the nineteenth century, Australian law permittedcolonial governments to order capital punishment for crimes that were no longer punishable by death in England, including attempted murder, robbery under arms and, most controversially, rape. Australian lawmakers knew their obsolete criminal codes reflected badly on their reputation as merciful and enlightened. Yet when politicians proposed the abolition of the death penalty, they faced strong opposition. All agreed that an effective criminal justice system held an important role in securing colonial authority and power, but they differed in their conception of the best way to achieve this end. This article examines public debates about capital punishment from the 1840s onwards, with a focus on the highly politicised issue of the punishment for rape. Despite a long-standing reformist campaign,successive New South Wales governments did not back down. Instead, they retained capital punishment for rape until 1955. Most political leaders thought it necessary to maintain this penalty to control two groups - Aboriginal men and white men from poor moral backgrounds - arguing they equally threatened white colonial women's virtue. Capital punishment for rape thus became an overtly violent symbol by which the colonial state asserted itself as the true guardian of female purity.