Play video content EXCLUSIVE

George Zimmerman used a gun to threaten his estranged wife Shellie and her father -- this according to the 911 call obtained by TMZ -- and she was terrified he was going to shoot them.

Shellie Zimmerman placed the call, claiming George had punched her father in the nose and was making threats with his hand on his gun. She says, "He's just threatening all of us with his firearm ... he's gonna shoot us!"

Shellie says George also smashed her iPad and slashed it with a pocket knife. She added, "I don't know what he's capable of."

Shellie filed for divorce from George last week.

Police detained and questioned George at the home in Lake Mary, Florida, where Shellie's parents live. George has not been arrested, and has reportedly already left the home.

1:42 PM PT -- Lake Mary Police Chief Steve Bracknell tells us, Shellie and her father have declined to press charges and George will NOT be arrested.