Psycopath? Driven? Insane? Obsessed? What? Show me the holes!
Persistent.
Obsessed
Detached Yeah, they're dead, they're...all messed up!
Ruthless.Whitey Bulger
Exemplary ----My Top 1,000 Favorite Films: http://www.imdb.com/list/ls071561044/
Merciless
Opportunistic ManipulativeRoboticUnsympatheticRuthlessInsane
The meaning of "one word" apparently escapes you!! ..*.. TxMike ..*..
Sociopath
Psychopath, for sure. Perfect match for Gyllenhall's creepy-weird features.
Yep that’s the word!