|Voice actor:||Allen Wenger|
|“||The best in the east town.||”|
– Officer McCarthy complimenting the coffee at Doc's Diner
Officer McCarthy seems to like the waitress of the diner, Kate Morrison, and doesn't leave the scene even when excused, so he can comfort Kate. He is also very fond of her coffee.
A time comes when Officer McCarthy and Lucas Kane are in the same place, at a park where a child had fell into the water and can possibly drown. It's up to the player to decide whether to take advantage of the commotion and escape unseen, or risk being caught and save the child. If Lucas decides to save the drowning child, Officer McCarthy will instantly recognize Lucas but allow him to quietly walk away for saving a life. He will later confess this incident to Carla Valenti.
- Martin's patch number is 823.