(Santa Clara, CA)  --  Problems continue to stack up for San Francisco 49ers linebacker Aldon Smith.  He's already facing DUI charges, and now prosecutors in Santa Clara County have filed three felony charges for possession of assault weapons.  The 24-year-old Smith and former 49ers tight end Delanie Walker have been named in the two lawsuits filed by alleged victims of a shooting that happened at the linebacker's house in June of 2012.  Smith remains on indefinite leave from the 49ers, more than two weeks after entering in-patient rehab for substance abuse.