Sebastián is a partner of Dal Pozzo Medina Abogados. He was part of the Court Unit of the South Metropolitan Regional Prosecutor’s Office of the Public Prosecutor’s Office, and acted as Chief Lawyer of the Judicial Area of the Ministry of the Interior of Chile. He has also been a professor of criminal law, criminal procedure, and oral litigation in undergraduate and graduate courses in Chile and abroad.

He holds a law degree from the Universidad Diego Portales and a Diploma in Criminal Procedure Reform and Oral Litigation from the same university, with international specialization in oral litigation techniques at California Western School of Law, and the National Institute for Trial Advocacy (NITA) in 2009, both in the United States.