To look carefully at something to find out the truth. (verb)
A: What is investigate?
A: What is a witness?
A: Two teenagers were painting graffiti.
A: Past Simple — completed action
A: "What were you doing..."
Q: The place where a criminal goes after being convicted. (noun)
A: What is prison?
A: What is a suspect?
A: True. Negative: was/were + not + verb-ing.
A: were arresting
A: "Can you describe the man?" or "What was he wearing?"
Marks left by fingers at a crime scene used as clues.
A: What are fingerprints?
A: What is a forensic scientist?
A: were having
A: were stealing (continuous) / rang (simple).
A: Medium height, dark hair, wearing jeans and a yellow sweater.
A: What is hijack?
A: Who is Sherlock Holmes?
A: was sleeping — action in progress at a specific past time.
A: They thought they were repairing the flat.
A: He/She ran away / called the police.
Q: Information or objects that help prove what happened in a crime. (noun)
A: What is evidence?
A: What is a burglar?
A: A boy was hitting his classmate. A teenager was riding a skateboard.
A: A Sherlock Holmes story.
A: "What happened?" + "What did you do?"