Melinda Stone was an ATF special agent. At some point, she went rogue and began selling weapons to various arms dealers which in turn had her superiors at ATF worried and they conducted a secret undercover operation with the help of NCIS Special Agent Leroy Jethro Gibbs. Having met Anthony DiNozzo beforehand, Stone agreed to help NCIS find out who was responsible for the weapons, not realizing she was being manipulated or lured into a trap. She and Corporal Patricia McClain were both eventually exposed, arrested and jailed as a result.