Grenades missing

At the monthly count, the depot numbers didn't add up. Some said a little was missing, others said a lot, and a few said there had never been anything there. The clues no longer hand you everything on a plate.

Suspects

• Aurora, the depot lieutenant: She did the count and noticed the shortfall. She counted again to be sure. The same was missing.
• Belmiro, the guard soldier: He was on guard at the door. He says the door was shut the whole time, which is true.
• Cassiano, the driver: He moves equipment between depots. That month he moved more than the log says.
• Diamantina, the signals corporal: She spends the day in the tower with the radio. She sees everything from above, except what happens underneath.