Well, it seems that our worst fears have come true: Grizzled photojournalist Frank West is indeed ready, willing, and able to dress up like a 14-year old girl with a monkey on his sleeve. On the bright side, you're unlikely to come across this haunting visage by accident. The discovery was made by Mirage86 on GameFAQs' forum, who says that the key to unlocking Roll Caskett's closet is to beat the game on hard with an S-ranking, which required doing so in under five hours. But that's not all, you must also rake in "12,000 or so" zombie points in that time.
Naturally, it would require a great deal of effort and some hardcore gaming skills to pull off such a feat, or so one might assume, and would hardly seem worth the effort. Ergo, if you're spotted playing the game with the Roll costume on, then we'll all know that you have some serious issues.