The killer crossover is a crossover dribble that is EXTREMELY fast and leaves the defender wondering what happened as he is left in the dust.
It can involve one simple change of direction from side-to-side or it can be a series of moves. Again, the main component of executing this move effectively is QUICKNESS and this requires an advanced level of ball-handling.
The killer crossover has become extremely popular in today's basketball culture; it was pioneered by NBA player Tim Hardaway, who played for the Golden State Warriors and the Miami Heat(and some other team later on in his career).
Tim's version involved two moves. First, he would cross over to his left hand. Second, and almost in the blink of an eye, he would dribble between his legs from left to right and he was gone.
Here is a very good demonstration and explanation on how to execute this move:
The next generation version of this move was pioneered by NBA player Allen Iverson, formerly of the Philadelphia 76ers and now with the Denver Nuggets.
What he did was, while dribbling the basketball, he would lean his body in one direction with the ball under his dribbling hand.Once the defender thinks hes going that way, he quickly dribbles the ball over to the other side. (he used his forward momentum to keep the ball underneath his palm, otherwise it'd be a carry violation)
...and here's a very good demonstration on how to perform it: