Make a Team Game
Using a plain inkpad, take a clean thumbprint on a small index card for each kid who wants to play. Write the child's name on the back of the card. Mix up the prints and have the kids sort them into groups according to which prints look the most alike. Those will be your teams.
Whodunit? Game
Lure the kids in with a spooky yet age-appropriate mystery story, using a prop like a broken plant feeder or half-eaten cookie. Select one fingerprint card at random and place it near the scene of the crime. Each team will elect one team member to be the head detective as they compete to identify the perpetrator before the other team does. Teams will make prints of each member on their team and compare them with the crime scene.
Fingerprint Trivia
Now that the kids understand what fingerprints look like and how they can be used, expand their interest by distributing a fingerprint trivia game. Gather information from websites such as http://www.funtrivia.com/playquiz/quiz1703081380ce8.html and allow kids to guess by themselves, in teams, or as a whole group.
Fingerprint Memory Game
Take out the first and second round of fingerprint cards. Place all of the first-round cards on the floor, print-down, and put the second-round cards into a single pile. Taking turns, have each child pick up a card from the pile and then select a face-down card to match it in a classic memory-style game. Have each child take a turn until all of the cards have been matched.