US man held after \'Facebook murder\' of wife

A US man is being quizzed by police on after gunning down his wife and posting a gruesome picture of her dead body on Facebook, authorities said. Derek Medina, 31, was being questioned by detectives in Miami after turning himself in earlier Thursday following the shooting death of wife Jennifer Alfonso, 26. In a macabre twist, Medina had apparently posted a picture showing his slain wife\'s blood-soaked body on Facebook, under the caption \"RIP Jennifer Alfonso,\" before giving himself up. In a status update posted shortly before the photo was uploaded, Medina wrote: \"You will see me in the news.\" \"Im going to prison or death sentence for killing my wife love you guys miss you guys takecare Facebook people you will see me in the news,\" he wrote. \"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.\" Police said Medina drove himself to the South Miami Police Department following the shooting. \"Officers then responded to the listed location where they found the victim deceased from apparent gunshot wounds, as well as the victim\'s daughter, 10, who was unharmed,\" a statement said. \"The motive is unknown at this time.\" Medina\'s Facebook page showing the picture of his dead wife was up for several hours before being taken down later Thursday. Beneath the photo -- which was shared 170 times before the page was closed down -- were comments from people who appeared to be friends with the dead woman. \"That is my friend there, Jennifer Alfonso,\" one woman wrote. \"What happened?\" asked another. Local media reports quoted Medina\'s father, Derek Medina Sr, as saying his son had killed his wife after a violent domestic dispute. \"He just said that his wife picked up a knife on him, and they had a big fight, and he shot her,\" Medina said. According to the Miami New Times blog, Medina once penned a self-help book online entitled: \"How I Saved Someone\'s Life and Marriage and Family Problems Thru Communication.\" Medina\'s neighbors meanwhile described him as a self-appointed neighborhood watchman who patrolled the area with a concealed gun. \"He walks around with a concealed gun, so he tries to be the neighborhood watch guy,\" neighbor Yoshi Dade told NBC Miami. \"He\'s always there late (at) night, and he\'s weird to me. He\'s always kind of looking around and trying to be a hero.\"