It is difficult to tell if he is a psychopath or simply narcissistic, with very strong antisocial traits. The cruelty to animals, cruelty to unknown and known persons as well as a complete disregard for social norms, respect and conventions supports your belief however.
Without doubt he clearly has anger and aggression issues and is self centered, untruthful, deceptive and self absorbed. However, true psychopaths, in the purest diagnostic sense have no conscious whatsoever, and are the ultimate self for self in terms of motivation. This could be the case here but there is the issue of the apology statement that he made in early 2010. This is an anomaly in the pattern and unless it has an ulterior motive, is uncharacteristic of the disorder.
Is he a sociopathic personality? Perhaps. He is definitely making a strong case for the diagnosis, that is for certain
What should you do? At his age, the odds that he will change are not good, guarded prognosis actually. Most experts simply say that the best way to handle someone with this issue is as you have, via avoidance. If you have to meet, meet only on your terms so that manipulation and harm potential are kept to a minimum.
I will say that you question is fascinating and I hope your book turns out well. You colleague appears to be an excellent person to avoid...