Professor Penna has taught in the Department of History & Government at Gallaudet since 1993. Before coming to Gallaudet he served the publications coordinator for the Center on Rights Development, Associate Editor of the journal Africa Today and as an adjunct professor at both the University of Denver and Colorado State University. Previously he served two years in the Peace Corps in Botswana.
At Gallaudet he serves as a pre-law advisor and coordinator of the mock trial program. He also serves on the Institutional Review Board, serving as chair from 2001-2007.
He has authored various articles and is co-editor of two books.