FBI

Joaquin "Jack" Garcia is a retired FBI agent who worked 24 of his 26 years in the bureau undercover. He spent three years infiltrating the Gambino crime family under the alias "Jack Falcone."

Mohamedou Ould Slahi was imprisoned without charge at Guantanamo Bay for nearly 15 years.

Ould Slahi speaks to Business Insider about the prison layout, the facilities, the food, and yard time. He reveals what torture methods were used and how guards interacted with detained people.