In Forensic psychology, criminologists and psychologists, observe two elements of crime notably:- Mens rea and Actus reus.
Mens rea - is the intention or knowledge of wrongdoing that constitutes part of a crime, as opposed to the action or conduct of the accused.
Actus reus - refers to the act or omission that comprise the physical elements of a crime as required by statute.
I’m yet to understand the motive (mens rea) whether intrinsic or extrinsic why the 23 year old university student, Lawrence Warunge bizarrely murdered his family members in cold blood. Aye, he may have admitted to have planned the heinous activity several months prior to the material day (actus reus), but he will be subjected to further mental examinations to ascertain his mental health status.
Most of these murderous psychos, terrorists, religious extremists, rapists, etc have innate motivations behind their criminal activities. It could be poor mental health, revenge, libidinal gratification, horror movies, etc. Remember the case of serial killer Onyancha? He was schizophrenic. When probed further by detectives, he said he heard “voices” telling him to murder his victims.
More cases of murders most foul will continue to arise in the future.