Sometimes otherwise inadmissible evidence may be introduced if the opposing party opens the door to it. The purpose of the “open-door doctrine” is to allow a party to rebut or explain something the other party has introduced:
State v. Simmons (dissent)
In a criminal case, if the defendant opens the door to inadmissible evidence, the solicitor will have at least two limits on introducing the evidence.
First, the evidence shouldn’t unfairly prejudice the defendant.
Second, the evidence must be proportional to how the defendant opened the door.