Christy Ryan (1974-2015) was one of the V.S.S.E. agents tasked with the agency's international affairs and (to a certain extent) intelligence auditing. She was killed 3 months prior to the events of Time Crisis 5.
Christy was a super-intellectual who graduated from both high school and Harvard University at an age earlier than anticipated. Being one of the few female agents of the VSSE, Ryan has a lot to prove. Posing as Diaz's administrative assistant, Ryan attempted leak information to the VSSE but was captured by Kinisky and the NDI security unit when Ryan's true intent was discovered.
Keith and Robert eventually rescued Ryan, uncovered the truth about the Starline Network, which was actually a network of military satellites intended to destroy the world. Fearing the dangers of her job, Christy was possibly trained to ensure the same thing didn't happen again.
In Time Crisis 5, the auditor's briefcase was never found which revealed the auditor was murdered three months prior to the game. When Luke O'Neil and Marc Godart fought Keith Martin, the wounded agent revealed that he was in love with the auditor, revealing the auditor to be Christy, who was murdered by Robert Baxter. Robert used Luke and Marc to cover up the briefcase's information, but when Keith made the young agents see Christy's laptop, players were duped all along, forcing (for the first time in a Time Crisis game) the players to have a change of heart.