Huge Plot Hole

He'd have to wait for Oswald to return in 1962, kill him, make an escape across country, check, then if it didn't, go back and wait years again. It's explained a lot better in the book. :-)

would not answer q about whether he acted alone

I was thinking the exact same thing myself. Kill Oswald, return to the future, see if it made a difference, and if not, reset.

Reading the comments below I understand the having to wait until he returns from Russia in 62, but again, why not off him the minute he returns and save yourself the year+ wait?

For that matter, why not just travel to Russia and kill him the first chance you get?

If you killed Oswald immediately and in the future Kennedy had still been assasinated, then wouldn’t that tell you he wasn’t acting alone?

Two problems:

1) He had to confirm that Oswald acted alone. According to Al, the attempted assassination of General Walker in April of '63 would be the proof.

2) He had to get all the way back to Maine in order to escape to the future. While anyone from the future, who knew what was going to happen would consider him a hero, but everyone in the past would simply consider him a murderer. If you kill Lee right at the airport, or anywhere else in public, there's a good chance he'd be arrested and spend the rest of life in jail. So if he did it when he was going to kill the General, or right before he shot Kennedy, then he would let off killing Lee. And even when he did save the President, the FBI still gave him a hard time.