MIAMI -- A Florida man who killed his wife and posted a photo of the bloody corpse on Facebook was convicted Wednesday of second-degree murder after failing to convince a jury that he shot her eight times in self-defence.

The jury verdict came in the third week of Derek Medina's trial in the August 2013 killing of 27-year-old Jennifer Alfonso at their South Miami home. Medina told police in a videotaped statement he shot his wife during an altercation in which she threatened him with a knife.

Medina, who did not testify in his own defence, admitted in the police statement taking a cellphone photo of his dead wife's body and uploading it on Facebook, along with a posting that said he expected to go to prison but was forced to kill her following years of physical abuse.

Prosecutors put on evidence indicating that Medina had vowed to kill Alfonso if she tried to leave him, which she told friends she planned to do. They also pointed out that at 6 feet and about 200 pounds, Medina could have easily overpowered his 5-foot-6 wife without shooting her.

"He planned to execute Jen, and he executed his plan," prosecutor Leah Klein told jurors in a closing argument. "He was angry and he wanted her dead."

Alfonso's mother, Carolyn Knox, burst into tears when the verdict was read after about six hours of jury deliberation over two days. She declined comment to reporters. Medina's father, also named Derek Medina, would not comment.

Medina showed absolutely no emotion as he was handcuffed and led back to jail, where he has been held since the killing. His attorney, Saam Zangeneh, said there will be an appeal.

"We have to respect the jury's decision. We just don't agree with it," he said. "We think this is a self-defence case."

The second-degree murder conviction means that Medina, 33, faces a sentence of 25 years to life in prison. If he had been convicted of first-degree murder as initially charged -- which requires proof of planning and premeditation -- the life sentence would have been automatic.

Miami-Dade Circuit Judge Yvonne Colodny set sentencing for Jan. 11. Miami-Dade State Attorney Katherine Fernandez Rundle said in a statement her office would seek the maximum of life behind bars.

"No family should ever have to see their daughter killed and then exhibited worldwide on the Internet like some macabre trophy to a husband's anger as was Jennifer Alfonso," Rundle said. The evidence, she added, showed that "Derek Medina coldly murdered his wife to heal his own injured ego."

Trial testimony showed the couple began fighting in their upstairs bedroom because Medina had failed to wake up his wife early that morning to watch a movie, as he had promised. Investigators testified that Alfonso threw mascara containers and towels at Medina, who pointed a gun at her in the bedroom but did not fire.

In a text message to a friend that morning, Alfonso said she "felt like ripping his face off" and was "about to explode" because of Medina's actions and added she just wanted more attention.

"I just want to spend time with him but I'm not going to beg," she wrote shortly before her death.

Later, the altercation continued in the downstairs kitchen -- some of it captured on one of the home's interior surveillance cameras. Medina told police Alfonso pulled a large kitchen knife on him and that he was able to disarm her, then went back upstairs for the gun and shot his wife when she kept fighting with her fists.

"She was trying to take me out," Medina said in the statement.

A medical examiner, however, testified that the eight shots were all fired downward toward Alfonso and that the position of her body on the kitchen floor indicated she had been cowering on her knees when killed.

Medina was also convicted of illegally firing a weapon inside a dwelling and with child neglect because Alfonso's 10-year-old daughter was in the home at the time of the slaying. The girl was in an upstairs bedroom and did not witness the slaying. But she was left alone for several hours while Medina went to turn himself in to police.

Defence attorneys sought unsuccessfully to admit evidence they said indicated that Alfonso was a heavy drug abuser and had dabbled in some form of Satan worship. They also were unable to get in evidence from a purported "shadow" expert they said indicated two upright figures were fighting in reflections in the kitchen's stainless steel sink.