CASSELBERRY, Fla. -- A woman with a history of mental illness shot and killed her 20-year-old son before killing herself at a Casselberry gun range, police said.

Marie Moore, 44, of Altamonte Springs, shot her son, Mitchel Moore, before committing suicide at about 4:20 p.m. at Shoot Straight Gun Range & Store, which is located on U.S. Highway 17-92.

"She ran out to get more ammo and went back in real quick, and all of sudden they were both down," witness Jim Copertino said. "(They were) both very anxious and hyper ... and then the shot happened right after that."

"Something went wrong. Literally, it was like a movie. I saw the man fall in slow motion. You knew he didn't have a chance. His life went just like this," said witness Bobby Davidowitz while snapping his fingers.

An investigation into the incident is ongoing.

Marie Moore's ex-husband said she was banned from the shooting range after trying to commit suicide there several years ago

The Florida Department of Law Enforcement has a database of people declared mentally ill or unfit by a court of law, and it's used to screen permits when people apply to purchase a firearm.

The state does not check, however, to see if gun owners have mental health problems when their licenses are renewed.