He is a member of the SPK and an FBI officer.
McEnroe first appears at the beginning of the Near-Mello story arc when he is sent to the Japanese National Police Agency HQ to request that the Death Note in their possession be handed over to the United States government, and thus the SPK. Soichiro Yagami, Deputy Director of the NPA, accuses the FBI of being involved in the kidnapping of Kanichi Takimura, the head of the NPA. However, McEnroe convinces him otherwise, and they agree to collaborate to rescue Takimura.
Takimura is later found dead, and Mello kidnaps Yagami's daughter, Sayu. This leaves Yagami with little choice but to travel to America and hand over the Death Note to the Mafia. After the exchange, McEnroe picks up the Yagamis by helicopter but takes them to a building in Los Angeles where Near questions them about the kidnappers.
According to "Death Note: How to Read 13," McEnroe survives the killing of the SPK agents through the use of the Death Note (see Chapter 66 "Death"). However, he is not seen again in the manga.
(Source: Death Note Wiki)
