What are some cases where a young man is arrested and questioned on a marijuana charge and becomes a suspect in a murder investigation?

The accused also relies on R v. Evans (1991) 1991 CanLII 98 (SCC), 4C.R. (4th) 144 S.C.C., where an accused was arrested and questioned on a marijuana charge and during questioning, the accused became a suspect in two murders. The accused was a youth of subnormal mental capacity who indicated he did not understand his rights when first given to him on the marijuana charge, and who was not given his rights again when aggressive questioning by the police took place with respect to the murder investigation. The S.C.C. stated that the accused was entitled to be advised as to his right to counsel a second time when the investigation turned to a different, more serious crime. This right does not extend to an exploratory investigation which touches on a different offence.