AmongJoJoposes, this one is a lot tamer, which fits Jotaro's stoic personality. It's also worth pointing out (pun intended) that this pose was inspired by Clint Eastwood's Dirty Harry character but using the finger instead of a gun. Araki has gone on record saying that Eastwood's loner...
While for most of the poses the hands are drawn as mittens for this particular pose you can actually draw out the trigger finger while still combining the rest. For an up close example of how to draw a hand holding a gun see: 6 Ways to Draw Anime Hands Holding Something Step 6 – Dr...