Three others face charges of obstructing the investigation.
Authorities said the attack was in apparent retaliation for an assault on Isiah Ruffin, 20, of Atlantic City, three days earlier.
While the two Ruffins were not related, Smith and Isiah Ruffin are first cousins, authorities said.
Smith, Sanders, and Hicks also face robbery and weapons charges. No one is currently charged with murder.
Smith's father, Ronnie Ruffin, 42, of Lindenwold, and his brother Henry Ruffin, 40, of Williamstown, were charged Tuesday with tampering with a potential witness in the investigation, authorities said. Neither is related to Nadirah Ruffin but both are uncles to Isiah Ruffin.
Henry and Ronnie Ruffin are accused of using force and threats of force to try to prevent Isiah Ruffin from talking to the FBI, according to court records.
Isiah was charged with giving false information to FBI agents investigating the case.
Nadirah Ruffin, a graduate of Atlantic City High, had attended community college and most recently worked at a Ralph Lauren store in Atlantic City, said attorney James J. Leonard Jr.
The chain of events that ended in Nadirah Ruffin's death began in suspicions of romantic infidelity, according to court documents.
According to prosecutors, on March 23, a woman they identified as "T.W." and said was romantically involved with Isiah Ruffin struck him and Nadirah Ruffin because she believed the two were also romantically linked.
Another woman, who lived with Nadirah Ruffin in the rented Atlantic City apartment, confronted T.W. after the assault. This woman, not named by authorities, told T.W. that Isiah Ruffin had grabbed her buttocks and directed sexual innuendos at her.