Percival Mabasa was shot dead in October when he drove into his radio studio.
According to the BBC he had reported on allegations of corruption by Bureau of Corrections director general Gerald Bantag.
Police have also charged Bantag’s deputy security officer Ricardo Zulueta with murder. The alleged hired gunman Joel Escorial turned himself in last month after his face was captured from CCTV cameras.
According to Al Jazeera Mabasa was murdered by two assailants who were hired on a $9,400 contract.