Put the synthetic blood of blood type you determine is the killer’s in a dropper bottle labeled “killer” and the blood type you designate as the victim’s in a dropper bottle labeled “Roger Rabbit”.
Cut out UPC labels from 4 different products. Cut out an extra UPC from one of the products to represent the killer’s DNA Profile. You can have one set for the class or sets of the 3 suspects DNA Profiles (UPC’s) for each group. Keep a copy of the UPC that represents the killer for yourself. When students determine who the killer is, have them compare the DNA Profile for that suspect with the killer’s. I laminated the UPC’s so that they could be used year after year.