A Dodge County grand jury has cleared an Owatonna police officer who shot and killed a man during a drug investigation last year.Police Sgt. Joel Welinski was part of an undercover operation with other agents in August 2008.At one point the suspect fled in his vehicle, striking and injuring a BCA agent.Welinski responded by firing at the suspect.Twenty-six-year-old Mario Alejandro Molina-Campos of Rochester died of his injuries.The grand jury announced its decision Friday.