SB Nation Bay Area contributor Bay Area Sports Guy has a lot more information on the incident. He includes details, originally reported by Matt Barrows of the Sacramento Bee, that the Santa Clara sheriff's office responded to reports of gunshots and arrived at the party to find over 100 people in attendance. Two people had suffered gunshot wounds and another had stab wounds. All injuries were non-life-threatening.
A source of Bay Area Sports Guy has been in attendance at several parties this offseason at Smith's San Jose mansion and said that these huge gatherings were not out of the ordinary.
Smith's parties include "no real security, no control, lots of 49ers in attendance, and prevalent drug use among guests," according to the source, who spoke on condition of anonymity.
For a lot more information, including video of a past party, please visit the story at Bay Area Sports Guy.