10 Huge Questions That Undermine Back To The Future

3. Why Doesn't Doc Brown Take Better Precautions To Avoid His Death?

I've briefly mentioned how Marty gave Doc Brown that envelope, telling him about how he was going to be shot in 1985. The Doc chose to take the precaution of wearing a bullet-proof vest, which saved his life. It's a touching moment in the film, that he silently admits that Marty was right by showing him the sellotaped letter from the past. But why doesn't Doc Brown take better precautions? Like, not stealing plutonium in the first place? He's had thirty years to think of this, and he's had thirty years' head-start to work out how to build a time machine: would he even run it on plutonium the second time around? The letter's a big vague about how he's going to die too: why doesn't Marty write in big capitals to avoid terrorists at all costs? Another big question though, is how the Libyans actually found him. How did they know he'd be at Twin Pine mall at 1:30 in the morning? Also...