Swabbing of Cotton

My apologies for I can't think of a better title. Okay, earlier this morning, we went to the Hall of Justice. We attended a hearing because our supervisor, the person who supervises us, was the witness.

Later in the afternoon, we took some pictures then performed the cotton swabbing or swabbing of cotton(whatever that is), then we took some more pictures.

Cotton swabbing or swabbing of cotton(whatever that is again) is one of the simplest things we learned in the history of our crime lab days. All you have to do is to clean or swab the gun with cotton. That simple!

The main purpose of this is to learn whether the weapon was fired or not fired by checking the cotton(with the gun powder nitrates presumably) by using DPA or diphenylamine to the cotton sample.