Benjamin Horlacher was a Naval officer who was a part of Guyman Purcell's class.
As well as that, Horlacher was a closet transsexual who cross-dressed, preferring to wear women's clothing.
Horlacher soon received a pair of human eyeballs in the mail from a mysterious source which prompted NCIS to investigate with Special Agents Leroy Jethro Gibbs, Anthony DiNozzo and Caitlin Todd later interviewing Horlacher in hopes of finding out who could have sent him the package but Horlacher insisted he didn't know anything.
After the interview, Gibbs dispatched Tony and Kate to stake-out Horlacher's place as he felt that the Petty Officer was hiding something.
At some point during the evening, fearing his secret could come out and unable to cope anymore, Horlacher put on some women's clothes and then wrote a note saying "I am free" before taking out a gun and shooting himself in the heart with the sound of the gunshot alerted Tony and Kate who had been staking out Horlacher's apartment, prompting them to storm the apartment and eventually discover Horlacher's body.