Question :Multiple different freeze frames in layers

Hey guys n girls…

Just beginning with Sony Vegas Pro 12 and would like to create a specific effect which I don't know the name of so can't even search for instructions in the Vegas tutorials.

So I'll try my best to describe.

I have a clip with someone moving through the clip doing an aerial stunt.

I want to freeze about every half second but keep that freeze and subsequent freezes all the way to the end of the clip as it keeps playing so by the end of it I've got the person performing the stunt in multiple positions across the arc of their stunt.

Please can someone name that effect and ideally link me to the vegas instructions on how to make it happen.

cheers

Nick