Instruct the interview team to question witnesses while the other investigators block off the crime scene with yellow tape. Remind them to avoid contaminating the scene. Tell the interviewers to write down what they observe during questioning, such as whether a witness has chocolate on his shirt or around his mouth. Perhaps he smells strongly of cheddar cheese or his tongue and lips are red from the juice. Witnesses may accuse the guilty party or give a physical description of the perpetrators, but they may also decide to lie to protect themselves or their friends. Circumstantial evidence assists in deciding who to focus on and who to discard as suspect in the investigation.
Direct the bite mark investigators to have each witness bite into a piece of fudge or cheese and to mark the evidence with a toothpick flag containing the name of the witness. These will be compared to evidence from the crime scene.
Assist the fingerprint team in lifting powdered sugar or chocolate fingerprints from the scene with clear tape. Tell them, "Aha! These are thumbprints!" This will facilitate the fingerprint collecting process, requiring the team to only collect thumbprints from the witnesses onto a paper and write the corresponding name underneath.
Tell the DNA investigators to compare the print sequence the perpetrators left on their drink cups to the sequences of each witness. The sequences can be similar to each other, but only two will exactly match the DNA left at the crime scene.
Help the students perform test spatters with juice. Explain that this will assist in profiling the offenders. A splash of juice on the chalkboard and crumpled cup on the floor could indicate aggravated criminal intent and could result in harsher punishment for the vandals, while a puddle from a tipped over cup could mean that the perpetrators were merely thirsty and careless.
Explain to the fiber team that they need to try to match the fibers from the crime scene to two of the witnesses in the room.