“Witness Infection” (*1/2 out of four) was a witless horror comedy about two rival mob families (Robert Belushi, Jill-Michele Melean, Vince Donvito, and others) who are both placed in witness protection mistakenly in the same city where havoc ensues and a bloodthirsty virus is on the rise that threatens them all. Lame mix of zombie horror with “Godfather”-style comedy based on a clever premise. Melean also co-wrote the strenuously unfunny screenplay. This one ought to sleep with the fishes.