Well, without more details it's hard to precisely tell the 'killer among friends real story'. However, in general, such stories often involve a breakdown in relationships. Maybe there was a long - standing feud over money, a love interest, or power within the friend group. And one friend finally snapped and committed a heinous act.
There are numerous 'killer among friends real story' scenarios. For example, in some cases, a friend might have a dark secret that they are desperate to keep hidden. When they feel threatened by another friend who might expose it, they could resort to killing. Another possibility is that a friend gradually develops a warped sense of reality and starts seeing their friends as enemies for no real logical reason. This can also lead to a violent and tragic outcome.
I'm not sure which specific 'killer among friends real story' you are referring to. There could be many such stories in real life where a person within a group of friends turns out to be a killer. It might be a case of jealousy, hidden motives, or psychological issues that lead to such a tragic situation.