The Los Angeles County district attorney's office said a criminal complaint filed Monday accuses Smith of the 2008 killing of Maurilo Ponce, the 1999 killings of brothers Kevin and Ricky Nettles and the 2001 death of Dennis Henderson, the Los Angeles Times reported Wednesday.
The Nettles brothers were kidnapped from a car wash in Los Angeles by two people posing as police officers. They were found dead the next day after having been tortured and shot.
Dennis Henderson also was kidnapped, tortured and shot, a spokeswoman for the district attorney's office said.
Smith, 45, faces retrial for allegedly killing Maurilio Ponce, 31, of Lancaster, Calif., in 2008. His trial ended in a hung jury in April.
Smith played professional football with the Los Angeles and Oakland Raiders between 1991 and 1998, the newspaper said.