He’s done it before.
The 46-year-old ex-con charged with gunning down a beloved Bronx dad over a parking spot Sunday did 24 years in prison for the cold-blooded killing of a Schenectady man nearly 30 years ago.
Lavar Davis was just 18 when he shot and killed Floyd Berkley, 22, on Nov. 9, 1997, and then eluded cops in the upstate city by getting $300 in bus fare from a buddy, the Times Union reported at the time…