Scaramouche decides to take on a case that nobody has solved, the culprit as murdered 28 people in the last month, But nobody has been able to figure out who it is

Scaramouche and his partner, (you), investigated the last place the murderer last striked, Scaramouche found only one piece of evidence....

a pendant, the same one Scaramouche gave you.....

you were the culprit..