Factual error: Higgins finds a bloodstained bag in the dumpster. The stain is bright red. The blood belongs to a person who was killed late the previous night, around midnight. After being in the hot sun for many hours the blood would have oxidized and be closer to a brown color, not bright red.
Factual error: The lady who was killed had been using a shredder "for over ten minutes straight" the night she was killed, according to the handyman. Nothing was apparently missing, though. The next day it turned out that what she received was an employment contract. No matter how many pages the contract was, it does not take ten minutes to shred.