This post has been corrected; see note below for details.

The L.A. County district attorney's office said Monday a 911 caller who lied to Pasadena police, leading them to believe a young man they fatally shot was armed is being held as an illegal immigrant.

Oscar Carrillo, 26, was arrested last Wednesday for involuntary manslaughter in the death of Kendrec McDade, 19, who was fatally shot March 24 by Pasadena police Officers Jeffrey Newlen and Mathew Griffin.

Usually prosecutors have 48 hours to charge someone in custody or release them, but district attorney's spokeswoman Jane Robison said Carrillo is on an immigration hold requested by federal Immigration & Customs Enforcement.

The immigration hold asks officials not to release Carrillo because he is believed to be in the United States illegally. Robison said prosecutors are reviewing the evidence from Pasadena police.