Criminologists at Birmingham City University identify six types of Facebook killers Informer ... Derek Medina shot dead his wife Jennifer Alonso then posted a photo of her corpse to Facebook. A TEAM of criminologists studying Facebook murders has identified six personality profiles for killers who used the social network in their crimes. The team from the UK's Birmingham City University zeroed in on 48 killings over a five-year period in which Facebook had been a factor. One of the personality types was a "reactor," a person who reacts to content viewed on Facebook by attacking someone. British man Wayne Forrester fit the bill for a "reactor." Forrester killed his wife Emma after reading her Facebook posts claiming that they had separated and she wanted to meet other men. Another type, "informers," used Facebook to tell others that they intended to kill someone or had killed someone. An example of this was Derek Medina, a 31-year-old from Miami, Florida, accused of shooting dead his wife, 26-year-old Jennifer Alonso, at their home in August 2013 then posting a photo of her corpse to Facebook. The research published in the peer-reviewed Howard Journal of Criminal Justice was authored by Dr Elizabeth Yardley and Professor David Wilson from the university's Centre of Applied Criminology. Not to blame ... Researchers cautioned against blaming the social networking site for the violence. Dr Yardley said: "We wanted to see whether homicides in which Facebook was reported to have been involved were any different to other homicides and found that on the whole they are not - victims knew their killers in most cases, and the crimes echoed what we already know about this type of crime." Dr Yardley cautioned against blaming the social networking site for the violence. She said: "Facebook is no more to blame for these homicides than a knife is to blame for a stabbing - it's the intentions of the people using these tools that we need to focus upon." The six personality profiles identified by researchers are: Reactor - Reacts to content posted on Facebook by attacking the victim face to face. This may be immediately after viewing the content that makes them angry or there may be a time delay in which they revisit the content and ruminate over its meaning. Informer - Uses Facebook to inform others that they intend to kill the victim, that they have killed the victim, or both. Informers use Facebook as a way of demonstrating their control over the victim and the situation. Antagonist - Engages in hostile exchanges on Facebook that escalate into face to face fatal violence. Antagonists may seek to introduce a physical advantage when the conflict goes offline through arming themselves with weapons. Fantasist - Uses Facebook to perform or indulge in a fantasy. For fantasists, the line between fantasy and reality has become increasingly blurred and the homicide may be a way of maintaining the fantasy or preventing others from discovering the deception. Predator - Creates and maintains a fake profile to lure a victim and meet them offline. May draw upon the information available on the victim's profile to identify and exploit vulnerabilities to establish grounds upon which to develop a relationship Impostor - posts in the name of someone else. This could be the victim in order to create the illusion they are still alive or another person to gain access to and monitor the victim's profile.