shoot to pieces
1. To shoot something multiple times and thus break it into pieces or destroy it. A noun or pronoun is used between "shoot" and "to pieces." The gangsters shot the poor man to pieces right on the doorstep of his house. Rebel soldiers shot the government building to pieces during their attack.
2. To find or point out the flaws in some argument, thesis, assertion, etc., through excessive analysis or criticism. A noun or pronoun is used between "shoot" and "full." The scientist spent the whole debate shooting his opponent's conspiracy theory to pieces. I thought my idea was pretty clever, but my PhD supervisor shot if to pieces.
shot to pieces
1. slang In poor condition. After dropping my phone so many times, the screen is shot to pieces. I'm sorry, what's your name again? My memory is shot to pieces anymore.
2. slang Having failed or gone awry, as of an idea or plan. We really need to regroup now that our proposal is shot to pieces after the meeting with the CEO.