Adjective: unrepenting
- Not penitent or remorseful
"The unrepenting criminal showed no regret for his actions";
- impenitent, unrepentant, unremorseful
- Stubbornly persistent in wrongdoing
"His unrepenting refusal to apologize only made the situation worse";
- cussed [informal], obdurate, obstinate, unrepentant
See also: unashamed, unregenerate, unregenerated