The lawsuit makes public for the first time the names of all seven people who had piled into the two vehicles that night, charging that while some were directly responsible for assaulting and killing Mr. Anderson, others were negligent because they acted as lookouts and did not try to help Mr. Anderson.
One of the people yelled “white power” during the attack, and others used a racial slur and bragged about the killing, according to the investigators.
The district attorney for Hinds County, Robert Shuler Smith, has said he will try to implicate other teenagers when he takes the case to a grand jury, expected to happen this month.
The F.B.I. has also gotten involved, with civil rights investigators helping Mr. Smith piece together the case, which was hampered early on by missing evidence and holes in some initial police work.
Mr. Smith has said he intends to prosecute the case as a hate crime, which comes into play during the sentencing phase. If Mr. Dedmon is convicted of capital murder and the prosecutors can prove that the crime was committed because of the victim’s race, the sentence may be doubled. The prosecutors have not decided whether to seek the death penalty for Mr. Dedmon.
The victim’s family has created the James Craig Anderson Foundation for Racial Tolerance, but has not spoken much publicly about Mr. Anderson’s death. In an interview with The New York Times last month, family members described Mr. Anderson as a good country cook, a gifted gardener and always genial. They said he liked his job on the assembly line at the Nissan plant, which he had held for about seven years.
“If you met him, the first thing you were going to see was that grand-piano smile,” said his eldest sister, Barbara Anderson Young, who is one of the plaintiffs.
James Bradfield, Mr. Anderson’s partner of 17 years, is not a plaintiff. Under Mississippi law, same-sex partners have no claim in civil actions like this, Mr. Dees said.
There was no indication that Mr. Anderson’s sexual orientation was a factor in the crime.