Via Entertainment Weekly:
Deep inside a compelling Washington Post profile of George Lucas is the Star Wars creator defending perhaps his most infamous bit of Special Edition tinkering: having Greedo shoot Han Solo first rather than the scruffy-looking smuggler taking a pre-emptive action.
Lucas says Han shooting first in the Mos Eisley cantina — which is what happened in the original edit of 1977’s debut Star Wars film — ran against the character’s principles. “Han Solo was going to marry Leia, and you look back and say, ‘Should he be a cold-blooded killer?’” Lucas asks.