He held a number of important posts throughout his career, serving as the first intendente (mayor) of Hurlingham Partido from 1995 to 2001, as Minister of Justice during the presidency of Eduardo Duhalde from 2002 to 2003, and as a National Deputy from 2003 to 2011.

Having belonged to the Justicialist Party throughout most of his career, in 2008 he joined the Light Blue and White Union, aligning himself with the opposition to then-president Cristina Fernández de Kirchner.

In 1997, he briefly requested for a leave of absence from his post to serve as Secretary of Community Relations in the provincial ministry of education, then led by Eduardo Duhalde.

[3] In October 2001, he resigned from his post as mayor to take office as Minister of Security of Buenos Aires Province in the cabinet of Carlos Ruckauf, whose presidential bid Álvarez supported.

[2] In 2005, following the Cromañón disaster, he was appointed by City of Buenos Aires mayor Jorge Telerman as secretary of justice and security; he served in the post for less than a year.

[8] A 2006 report by Página 12 journalist Victoria Ginzberg revealed Álvarez had collaborated for the Secretaría de Inteligencia (SIDE), Argentina's intelligence agency, in 1981, during the country's last military dictatorship.