David Tembe's Public safety career began in 1981 as a paramedic with the Johannesburg Emergency Services (EMS). He became a Superintended in 1989, and in 1999 was appointed acting Director in charge of the EMS Academy.

Tembe was appointed Director of Operations in 2001, where he was responsible of leading the 26 city fire stations.

In 2002 Tembe was appointed acting Chief of the Emergency Management Services, where under his stewardship, the URBAN Search and Rescue was established and represented South Africa during Algeria and Iran’s disasters.

After serving for close to 20 years with the EMS, Tembe was appointed Director of Operations for the Johannesburg Metro Police Department (JMPD) in 2003. During his time with JMPD, he was awarded and commended by the National Department of Transport for innovation and excellence in Traffic Law Enforcement. In 2011, Tembe was appointed National Chief of Traffic (RTMC) until he resigned to pursue a career as a consultant in Law Enforcement in 2013.

Tembe holds a National Diploma in Personnel Management, Metro policing, FBI Law Enforcement Executive Leadership (Virginia, USA). He has also attended seminars on Law Enforcement Leadership in the USA since 2009.

In January 2017 Mr. Tembe was appointed the new Police Chief for the Johannesburg Metropolitan Police Department (JMPD), and in 2020 joined forces with former Johannesburg mayor Herman Mashaba on his new party The People's Dialogue, now ActionSA.