People v. Comage 

Police officers stopped Defendant while investigating a reported gas station theft, and while officers were talking with him Defendant ran away, pulled two objects from his pocket and threw them over a six-foot-high wooden fence. Officers then walked around fence and recovered, 20 seconds later and ten feet away, a crack pipe and push rod used to pack drugs into a pipe. Defendant did not "conceal" physical evidence by throwing objects over fence; officers knew where evidence was and had no trouble recovering it. Although items were briefly out of the officers' sight, Defendant did not materially impede their investigation and thus State failed to prove offense of obstruction of justice by concealing physical evidence. (KILBRIDE and THEIS, concurring; FREEMAN, specially concurring; THOMAS, GARMAN, and KARMEIER, dissenting.)