Lt. Hartenstein began his law enforcement career as a Deputy with the Denver Sheriff's Department in November of 1997. After working as a jail deputy for over a year, he pursued a career as a police officer. He became a police officer with the Boulder Police Department in January of 1999. Lt. Hartenstein was a valued member of the Boulder Police Department for seven and a half years. He worked three years as a DUI Officer and over four years as a patrol officer.  He was chosen as one of Colorado's top DUI law enforcement officers and recognized as a "Heat Hero" at a state awards ceremony in 2001 and 2002. Shortly after Hurricane Katrina affected his family in Louisiana, Lt. Hartenstein decided to move back to the Gulf Coast to assist his family.

Lt. Hartenstein began his career with the Foley Police Department in January of 2007. After a short period of time as a patrol officer, he was transferred to the Criminal Investigations Division where he spent over 12 years as Detective and Supervisor. In addition, he was an investigator and later a Deputy Commander in the Baldwin County Major Crimes Unit from 2014 to 2020. In 2020, He was promoted to Lieutenant where he served a year and a half as a Commander of the Community Safety Division. He was the Commander over the Criminal Investigations Unit where he has served for over 2 1/2 years, but recently was moved to leading the Administrative divisions, also known as Corrections.