The Santa Fe county sheriff says the gun used by Alec Baldwin fired a suspected live round that killed a cinematographer and left a director injured.

Sheriff Adan Mendoza says the weapon handed to the Long Island-born actor was "functional and fired a live round."

He says what was being called a "dead" projectile was recovered from injured director Joel Souza's shoulder.

Investigators say they collected around 600 items of evidence, including three firearms, approximately 500 rounds of ammunition and several pieces of clothing and accessories.

They are now working on determining how a loaded gun ended up in Baldwin's hands.

"The people that inspected or handled the firearm when it was loaded before it got to Mr. Baldwin--we're interviewing," Mendoza says. "And there are some follow-up questions that we need to do."

First Judicial District Attorney Mary Carmack-Altwies says a complete, more thorough investigation needs to be completed before it is decided if any charges will be filed.

Officials say Baldwin has been fully cooperative in the investigation.