Fr. Calero arrived in 1990 at Santa Clara, where he taught anthropology and also served in different academic and administrative positions on campus. He was the Director of Ethnic Studies, acting chair and faculty member in anthropology, faculty fellow at the Ignatian Center, director of faculty/staff immersions to Central America, member of faculty/staff development programs, and team member in Campus Ministry.

He also taught at Jesuit universities in Guatemala, El Salvador, and Colombia. In 1989, when six Jesuits and two women were killed at Universidad Centroamericana in El Salvador, Fr. Calero taught periodically for five years in a school that had temporarily lost its leadership.

He has a bachelor's degree in philosophy from Loyola University, New Orleans; a master's degree in divinity from the Jesuit School of Theology in Berkeley, and a Ph.D. in Latin American Studies (anthropology emphasis) from U.C. Berkeley

Fr. Calero has been active in the Diocese of San Jose, celebrating liturgies in different parishes, particularly for immigrant communities.