Luna, 38, who for four years had been an assistant U.S. attorney in Baltimore, was found Dec. 4. in a rural Pennsylvania field. He had been stabbed 36 times. Investigators have found no evidence linking the killing to Luna's work and have said they think the killing was related to Luna's personal life.
Authorities have not identified any suspects in the case and have not made any arrests.
DiBiagio vowed the first night of the investigation that "we will find out who did this," but he has not commented on the case since. Asked twice about Luna yesterday at a news conference he had called to discuss another case, DiBiagio said his office had "dealt with this tragedy with the utmost professionalism." Asked a third question about the investigation, DiBiagio ended the news conference.