LEGO CITY Undercover

This is awarded for filling the yellow 'hero' bar in a level. The 2x multiplier red brick can be found in a prison cell during the Trouble in Stir special assignment of Chapter 3 (the prison level). When you complete this level, turn the multiplier on in the extras menu, then replay the 3rd level. Cheev will pop when the bar is filled. It took me about ten minutes to fill the bar with the multiplier on.