Mexico City, Jan 30 (IANS/EFE): A man has been sentenced by a Mexico City court to serve 50 years in prison for the April 20, 2012, murder of retired Gen. Mario Arturo Acosta Chaparro, judicial officials said.

Jonathan Javier Arechega Zarazua was given the long sentence by Federal District Criminal Court Judge Jacobo Cedeno.

The 22-year-old Arechega was identified by eyewitnesses as the man who fired three shots at the retired general.

Acosta was shot and killed at a garage in the western section of Mexico City.

In May 2010, the retired general survived a shooting during an attempted robbery.

Acosta Chaparro and the late Gen. Francisco Quiros Hermosillo were arrested in August 2000 on charges that they provided protection for the Juarez drug cartel for years.

The two officers were tried, convicted and stripped of their ranks by a military court in November 2002.

Acosta Chaparro and Quiros Hermosillo served their sentences at Mexico City's Military Camp No. 1.

Acosta Chaparro, however, was released on June 29, 2007, after a federal court threw out his conviction, citing lack of evidence linking him to drug traffickers.

The ruling allowed him to regain his rank of general.

Acosta Chaparro was also tried in connection with the massacre of 22 peasants during Mexico's "dirty war" in the 1970s, but he was acquitted in February 2006.