Smith entered an in-patient rehab two weeks ago, just days after he got his second DUI since January 2012.
He is expected to appear in court on Nov. 4 to answer those misdemeanor DUI charges, which allege is blood alcohol content was at least .15 - twice the legal limit.
Now, the Santa Clara, Calif., district attorney's office has filed three felony weapons charges against Smith. The charges spring from a June 2012 house party in which Smith was stabbed and two people were shot.
Smith and teammate Delanie Walker have already been hit with civil lawsuits stemming from the party that allege Smith owned illegal firearms. Neither suit alleges that Smith or Walker fired the shots at the party.
Smith is expected to turn himself in on the gun charges later this month.
Millions of Getty images now available for free via embed tool
Aaron Carter is still in love with Hilary Duff