From Longman Dictionary of Contemporary Englishthe guilty partythe guilty partyformalGUILTY the person who has done something illegal or wrong → guilty
Examples from the Corpus
the guilty party• How dared he act as though she were the guilty party?• Say they believed they had the guilty parties.• The Justice Department could not ask for damages or seek penalties against the guilty parties.• The rest of the audience cranes its collective neck to spot the guilty party.• And they'd find the guilty party: a giveaway print of designer lipstick mars the rim.• Some critics might favour the pragmatic solution of convicting both, to ensure that the guilty party does not escape justice.• Fines of up to 10 percent of the worldwide turnover of the guilty parties may be imposed.• Yet economic mismanagement at home will often be the guiltier party. % % Rrrrrrrrecession?