Rifle

Rifle is a technique that eventually results in two T-Spin Doubles. Usually, if there is nothing placed on the setup, one can make another T-Spin Double after the first TSD. However, if there is something on top of it, usually a tetromino or the fourth setup shown, it can become a T-Spin Triple after a T-Spin Double.

Setups
The fourth example will inevitably require a piece to be placed on top of the J piece and consequently, only a T-Spin Triple would be possible afterward.