Everett Miller: Who is the alleged gunman in the killing of Kissimmee officers?

OSCEOLA COUNTY, Fla. — The Kissimmee man accused of shooting, killing two Kissimmee police officers was a decorated U.S. Marine, Channel 9 investigative reporter Daralene Jones has learned.

Everett Miller has family in Orlando and the Kissimmee neighborhood where Officer Matthew Baxter and Sgt. Sam Howard were shot and killed Saturday night.

Read: Report: 'I have done a bad thing,' accused Kissimmee police killer tells detectives

His family didn’t want to speak on camera, but described him as a man with a history of mental issues for which he couldn’t get help.

Police believe it is Miller on a YouTube video at target practice shooting a 9mm.

“(It's a) weapon that is used by the United States military currently,” Miller said in the video.

Kissimmee police are reviewing the video and other social media posts they believe Miller made that may have signaled trouble.

In one post that featured a photo of Dr. Martin Luther King, Miller wrote, "You only can poke a tie up dog for so long. Once that chain breaks it's over. Wake up America before it's too late."

“We're going to look at every aspect of his life, any posts that he's put out on social media, try to get a feel for who he was,” said Stacie Miller with the Kissimmee Police Department.

Miller enlisted in the Marines in 1989. His 21-year career started in Tampa and took him from North Carolina to Japan, and he served twice in Operation Iraqi Freedom.

Miller was a decorated Master Sergeant with training in intelligence analysis. He was honored six times for good conduct, twice for outstanding achievement. Miller received on two occasions the Global War on Terrorism Service Medal. He separated from the Marines in 2010.

Eyewitness News learned in July, Miller was seen walking around a neighborhood of Old Dixie Highway in his underwear while carrying an assault rifle.

Miller could still face a weapons charge in that case. He was involuntarily taken into custody for a mental health evaluation after the rifle incident, but was released within three days.

Cox Media Group