Why does the Chauvin prosecution keep calling witnesses that help the defense?

This is a court of law. Sadly, most people believe that the trial by media and public opinion has already set the verdict. They just want the execution. It's not happening.

That is not their intent lol. It's just backfiring on them. Court trials all bring up witnesses btw. 

Because the case they have against Chauvin is weak.  The only way he'll be convicted is if Democrat-sponsored BLM & ANTIFA thugs can intimidate the jury with threats of mass insurrection.