Did you use the evidence photo from the front of the building, and the person of interest sheet for Broc to get your answer for this objective? If not, go back to those two documents and check out what you can find! Here's a hint: you might need a magnifying glass! If you did use those two documents, scroll down for the answer!
Great detective work! You matched up the license plate listed on Broc's Person of Interest Document with the license plate on the vehicle in the foreground of the crime scene photo taken at 9:38 pm. This doesn't mean that he is the killer, but it does mean that he lied about his alibi and WAS in the area during the party, and the murder! Now you can open up bonus envelope B!