Captain Frenzel joined the NJ Transit Police in 2004. He began his career assigned to the Patrol Division in Transit District 2 and also served in the Office of Emergency Management and the Hazmat/Emergency Service Unit.

Captain Frenzel was promoted to Sergeant in 2012, Lieutenant in 2022, and Captain in 2025.  Captain Frenzel holds a Bachelor of Science in Sociology and minor in Criminal Justice from Saint Joseph's University. Captain Frenzel is a graduate of the 87th Class of the Burlington County Police Academy where he was the recipient of the High Academic Award.

Captain Frenzel is the recipient of the Excellent Police Service Award and 2 Unit Citation Awards.