Before the Board of Regents approved the upgrading and thus the creation of the Public Safety and Security Office (PSSO) on 31 July 2019, there was the Chief Security Officer (CSO).
On 1 May 2011, Prof. Elvin R. Ebreo from the College of Arts and Letters was appointed as the first CSO of UP Diliman by then Chancellor Caesar Saloma. The responsibilities of the CSO include:
- Overall supervision and control of UPDP personnel, security guards and SSB personnel deployed in UP Diliman;
- Chairs the UPD Security Committee that will be formed by the Chancellor;
- Ensure the enforcement of the Terms of Reference in the contracts of security agencies;
- Shall be directly accountable to the Chancellor;
- Shall regularly report to and/or brief the Chancellor on security matters in UP Diliman; and
- Perform other tasks that may additionally assigned by the Chancellor relating to security matters and/or concerns in UP Diliman.
Prof. Edgardo Dagdag was appointed as the second CSO from 12 March 2012 until 31 May 2012, followed by Atty. John S. Baroña, who served as Acting Chief Security Officer since 13 October 2013 until his appointment as Acting Director of the Transportation Management Office (TMO).
CSO was directly accountable to the Office of the Chancellor before he was transferred to the OVCCA in 2014 under the administration of then Vice Chancellor Nestor T. Castro. The CSO supervised the following: UP Diliman Police (UPDP), Special Services Brigade (SSB) and the Task Force on Squatting, Community, Housing and Utilities (TF-SCHU).