Conversation so far:
What is Chris Christie's view on firearms?
commuted the seven-year sentence of Brian Aitken, who had been convicted of transporting three guns within the state; as a result, Aitken was released.
Did he release other prisoners?
CANNOTANSWER.
What happened after Aitken was released?
CANNOTANSWER.
Did he support any gun laws?
handguns.
In July 2014, Christie vetoed legislation that would have reduced the allowed legal size of ammunition magazines.

Question: Why did he veto the legislation?
Self-contained rewrite: Why did Chris Christie veto the legislation to reduce the allowed legal size of ammunition magazines?