I don't think the issue is the white stuff in the photo, he could be holding anything on the picture. The point is, through the picture they identified the pers

I don't think the issue is the white stuff in the photo, he could be holding anything on the picture. The point is, through the picture they identified the person whose hand it was, used detective work to identify his gang, raided their properties, and found drugs... And why did they "waste their time"? Because probably their chat was discussing their drug trade...