Member of the Natural Resources and Environment Group of Carey y Cía. His practice focuses on mining, water rights, industrial and natural resource projects, pharmaceutical matters, partnerships, joint ventures, contracts and real estate, and land use.

He worked at Cleary, Gottlieb, Steen & Hamilton, New York, USA from 2000-2001.
In 1998 he was an assistant professor of the Civil Law chair at the Faculty of Law of the Diego Portales University and is currently an assistant professor of the Mining Law chair at the Faculty of Law of the University of Chile.

He is a member of the Chilean Bar Association.

Mr. Mackenna studied law at the Pontificia Universidad Católica de Chile, graduating as a lawyer in 1997. He obtained a Master of Laws from Duke University, N.C. USA in the year 2000.