who can i get to help murder investigation?

[Marie]

I live in phila almost 6 yrs ago my triplet was murder and the detectives have done little to try to solve his case. I need help i beleive the girl my bro was seeing boyfriend stabb him because it happen right out side her apt building. We told the detectives this and they done little about it and from what i heard the girls boyfriend father is a Sergant or LT of the philadelphia police dept. I need help they cant get away with this. Not mention she was the one who told everyone my bro was dead before the detectives even came to notify us. She was out there that morning and claim she just came out and he was dead on the ground and seen his sneakers and knew it was him. How can u just know that if u didnt see his body u dont start telling family and friends someone is dead unless u no for sure and seen the body not just sneakers.