Limpopo police are investigating a case in which a 37-year-old man killed his girlfriend, raped her friend and then took his own life.Benjamin Tebogo Marema shot his 27-year-old girlfriend, Kholofelo Morerwa, in the early hours of Thursday, following an altercation over infidelity, according to the police."The quarrel between the couple allegedly started on Tuesday the 28th when the suspect, at about 21:00, arrived at his girlfriend's rented place and thereafter forcefully took her to her friend's place which is a few metres away," police spokesperson Brigadier Motlafela Mojapelo said."On arrival, an argument continued until the boyfriend fired shots at his girlfriend, killing her instantly. He then, at gunpoint, allegedly raped the friend before turning the gun on himself."The man and his girlfriend were declared dead on the scene.Police are investigating cases of murder and rape and have opened an inquest docket.Limpopo police commissioner Lieutenant General Nneke Ledwaba appealed to members of the community to seek professional help to resolve disputes instead of resorting to violence.