Published: Aug 13, 2010 10:32 PM EDT
Updated: Aug 13, 2010 7:32 PM EDT

LEHIGH ACRES, Fla. - The man who killed his daughter and grandson will face harsher sentencing.

Manuel Rosales will face the death penalty. Prosecuters filed the paperwork on Friday.

In May, three-month-old Josue and his mother Karminda Rosales Salazar had their throats slit by Rosales. Investigators said he made his daughter watch as he killed her son.