Lieutenant Mendez was a detective police officer charged with investigating the attempted murder of Anias Ruey, approximately 600 years before the time of Miles Vorkosigan. He was middle-aged and capable, but the shortage of useful leads resulted in a week of almost fruitless work for him.
When Anias and Chalmys DuBauer managed to flush her attacker, Carlos Diaz, out of the background and captured him, Lieutenant Mendez was disappointed to have contributed little, but worked with them to convince Diaz's employer to abandon his own murderous schemes.