Ramzi Yousef is a Pakistani Al Qaeda operative who participated in several high profile attacks on behalf of the terrorist group. Yousef was the lead in the 1993 bombing of the World Trade Center in New York City and a perpetrator of the 1994 bombing of Philippine Airlines Flight 434. He is also the nephew of Al Qaeda senior leader Khalid Sheikh Mohammed. Yousef was arrested in Islamabad, Pakistan in 1995 while trying to sell a bomb constructed inside a baby doll. He is currently serving a life sentence at ADX Florence, a supermax federal prison in Colorado.