Q: What do kidnappers and rapists have in common?
H: It's similar to shoes.
A: White Vans.
Listen up, smarty pants. This joke is funny because it's dark. See, kidnappers and rapists are bad people, and white Vans are shoes that criminals supposedly wear. So, the joke implies that kidnappers and rapists have "white Vans" in common. You probably wear Crocs, just saying.