The charges are connected to three incidents back in 2009 that investigators say happened when Antolin Garcia Torres was 17-years-old. One involved a stun gun.
Although no body has been found, the now 21-year-old Torres was arrested in May for Sierra's murder based on DNA evidence.
A fundraiser was held Saturday night to support ongoing efforts to find her. The ice skating event took place at Shark's Ice in San Jose. Organizers are holding out hope for the teen's safe return.
Sierra vanished on March 16th while walking from home to her school bus stop.