Could the firearm 'go off without the trigger being pulled'?
Marissa Poppell is now being shown a picture of the ammunition taken from the holster assigned to Alec Baldwin. She identifies the round she believed was live.
The court hears she also collected other holsters, one of which contained a suspected live round, and again she identifies this.
The live rounds look different as they have silver primers at the bottom, the court is shown.
Loose ammunition collected from the top of the props cart on set also included two suspected live rounds, she says, while the boxes of dummies retrieved included one suspected live round.
When the prop truck was later searched, with about 1,000 to 1,500 rounds examined, there were no live rounds found, the court hears.
The court is now being shown a picture of the projectile removed from Rust director Joel Souza's shoulder, which was also photographed and then sent to the FBI lab for examination.
Ms Poppell is now being asked about the FBI tests requested on the gun, which she says were to determine whether or not the gun could "go off without the trigger being pulled".
Asked about the search of PDQ Warehouse in Albuquerque, owned by Seth Kenney, the court hears the ammunition for Rust was supplied from here.
Live ammunition was found at the business, Ms Poppell says, but "visibly" it wasn't identical to that found on the set of Rust. The live ammunition collected from PDQ was also sent to the FBI so that gunpowder inside could be compared to that found in the live rounds on the Rust set, the court hears.