MIAMI -

Derek Medina, Jennifer Alfonso The 31-year-old man accused of killing his wife, then posting a picture of her body on Facebook was arraigned Thursday.

Sporting a thick beard, Derek Medina sauntered into the courtroom where his attorney, Saam Zangenph entered a "not guilty" plea.

It was a bit of a surprise for court observers, given this case isn't a who done it.

Authorities say Derek Medina posted a Facebook status on Aug. 8 in which he confessed to killing 26-year-old Jennifer Alfonso. Moments later, a gruesome photo appeared on the page of a woman slumped on the floor. Medina later told police he had gotten into an argument with Alfonso that day.

Both were eventually taken down by the social media site, but not before it was shared countless times.

That Facebook post included a claim of self defense. Medina said Alfonso punched him.

Medina's lawyer says he will explore different self-defense options once he reviews the evidence against his client.

Medina is charged with first-degree murder.

Earlier this month, a judge approved a request for preservation of evidence in the case. Three attorneys took over from the Public Defender's Office, which initially represented Medina.