Raise Reasonable Doubt? I think you have it backwards. The State has to prove he did it "Beyond a Reasonable Doubt." So while the defense attorney will try to bring reasonable doubt to refute the State's case, the onus is on the prosecutor to prove he did it BARD.
It's voir dire 101. Attorneys hammer this into the jury panel's mind. If the State were to put on all this evidence and the Defense literally did NOTHING, you could STILL have a reasonable doubt, and lack what is needed to convict. Theo is right, in reality, this never happens. The defense always puts on a case. But if the State doesn't meet their burden of proof, they don't have to.