Footage Shows Moments When Florida Man Allegedly Kills Wife

PHOTO: Video still of Derek MedinaPlayCourtesy Miami Herald/WPLG/ABC News
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Newly released footage from the home of Derek Medina, who is accused of fatally shooting his wife during a domestic dispute and caused a stir when he allegedly posted an image of her body to Facebook, shows him firing a gun in the kitchen of his Miami home.

Medina, 31, is accused of murdering 26-year-old Jennifer Alfonso in their South Miami home on Aug. 8. A home surveillance video released this week shows Medina walk off from a confrontation in the couple's kitchen and return moments later and fire a gun.

The footage was released Tuesday by Miami-Dade police. A gun is not visible in the video from the morning of Aug. 8 but a swirl of smoke is caught by the camera that is facing into the couple's kitchen. In the video, Medina is also seen grabbing a jacket and phone, then apparently taking a photo and walking out of the townhouse.

Derek Medina Shot Wife Multiple Times Before Posting Picture to Facebook, Search Warrant Says. Read more here.

Alfonso's death sent shockwaves around the world after a photo of a woman in a black outfit, slumped over backward in the kitchen with blood on her left arm and face, was posted on Medina's Facebook page around the time of the shooting, along with the apparent confession.

"I'm going to prison or death sentence for killing my wife, love you guys miss you guys, take care Facebook people. You will see me in the news my wife was punching me, and I am not going to stand anymore with the abuse so I did what I did. I hope u understand me," the post on Medina's Facebook page read.

Friends replied to the post in disbelief and asked Medina what had happened. His Facebook profile was removed about five hours after the shooting, according to ABC's Miami affiliate WPLG-TV.

Shortly after the Facebook post, Medina turned himself in at a South Miami police station. He has been charged with second-degree murder, but prosecutors are seeking a first-degree murder indictment, according to WPLG. Medina has pleaded not guilty and claimed he was acting in self-defense.

The Miami-Dade prosecutor's office has also released Alfonso's diary, which she titled "The Mind of an Insane Woman." The diary, which Alfonso had hoped to turn into a book, chronicles the ups and downs of her relationship with Medina. In one entry she says her husband's ogling of other women made her want to "rip his eyes right out."

"We have the strangest relationship, to me anyway," she wrote in a Dec. 27 entry. "We get angry at each other for the stupidest things." Later she wrote, "I find myself uncontrollably jealous, like want to murder type deal…" In a post in February, she wrote, " I [know] he loves me and I [know] I love him, I just wish we had better ways of showing it."

Excerpts from Alfonso's journal are available to read here.

ABC News' Alyssa Newcomb contributed to this report.