You're correct Steve, but it's not one gene responsible for antisocial personality and behaviour ( APB ). If it was, it could in theory be detected and targetted with a specific drug, like certain cancers.
A recent meta-analysis ( review of all studies on the topic ) showed that about 3/5 of the variance in APB can be explained by genetic influences, 1/10 due to shared non-genetic influences, and about 1/3 due to unique non-genetic influences. Interesting, but of no practical use.
( It's in The Journal of Social Psychology, 2010, 150(2), 160-180 ). http://www.tamiu.edu/~CFERGUSON/evmeta.pdf