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Notes for the Instructor

In the event of a crime, investigators will spend time interviewing people to figure out who was involved. One important thing to uncover is where people were when the crime was committed, or their alibi. Some people will easily be able to prove their alibi with another person as a witness, timestamped images from a camera, or other concrete proof such as a ticket stub or receipt. Other alibis are harder to prove. For example, if someone claims to have been home alone all night without seeing anyone else.

Sometimes a suspect will give a false alibi, or lie about where she was at the time the crime took place. Investigators must use keen listening skills and take detailed notes while listening to suspects’ alibis. Often the interviews are taped and later transcribed. This is because coming up with and remembering all of the details of a false alibi is very tricky to do. Very often a person who is not telling the truth will contradict his own story. The more talking the investigators can get the suspect to do, the more likely they are to break a false alibi.

Keep in mind that giving a false alibi will increase suspicion for the suspect, but it does not prove that she was involved with the crime. A suspect may give a contradictory alibi if she is lying to protect someone else, ashamed or embarrassed to give her true alibi, or has an impaired memory of her true alibi. The suspect may also give a false alibi because she is guilty! An alibi alone cannot lead to a conviction. It is up to the forensics team to use the rest of the evidence from the scene to solve the case.

In this activity, students will hear the alibis of four suspects. They will practice the skills of a forensic scientist by listening carefully to each story. Then, using matching picture cards, students will retell the details of each suspect’s story in sequential order.