He worked as assistant of the National Attorney, president of the "Universidad Distrital de Colombia", professor, Justice´s Vice-Minister, Minister of Justice, Magistrate of the Supreme Court of Justice and President of the Constitutional room.

 

​The magistrate Gaona was known for his emblematic decisions related to the limitations to the power of the police, the constitutional control for the Army and the separation of the political powers. Between others, also he defend the autonomy of judges and the constitutional immutability of the Supreme Court. ​He confrontted directly the drug cartels in Colombia due to the approbation of the Extradition between Colombian and the United States. He is considered as one of the experts in the judicial interpretation of the extradition, fact that confront him directly with Pablo Escobar. ​

 

Gaona died being a magistrate of the Supreme Court of Justice.  Days before his dead, he was in charge of the case of torture of the M19 guerrilla´s member, Olga López and other cases as the sentence to the Judicial Reform in the government of Julio Cesar Turbay, in which the purposes were to judge civilians by the Military Justice. ​​His dead has not being clarified and it is said that he also exit the Palace of Justice alive as magistrate Carlos Oracio Urán after the Assault and that he was victim of a extrjudicial execution of the Army Forces.