There will already be one in the chamber long before I need to shoot.
Both approaches are valid IMHO. I once disuaded a home invader by calmly walking to the door the scumbag was trying to break down and racking a round. Heard him/it scurry off instantly. Only evidence left was the puddle of urine outside my door. (No joke.)
You really should have taken a picture of the evidence. Might have caught a picture of a footprint after the perp had stepped in "it".