(CNN) -- The families of two men who were gunned down in Boston in 2012 have filed wrongful death lawsuits against former New England Patriots player Aaron Hernandez, according to court documents.
The $6 million lawsuits were filed Wednesday on behalf of the families of Daniel Abreu and Safiro Furtado, according to court papers.
Hernandez, who is being held on charges related to another slaying, has not been charged in connection with the deaths of Abreu and Furtado.
The lawsuits claim that Hernandez "recklessly" and "maliciously" shot a firearm from his vehicle into a vehicle carrying Abreu and Furtado, killing them.
The two men were shot and killed in Boston while riding in a 2003 BMW. Two others in the car survived.
At a news conference Wednesday, Salvatore Furtado said his son, Safiro, "was a good boy, a hard worker, very intelligent," according to a woman who interpreted his comments from his native Cape Verdean dialect.
Daniel Abreu supported the family and worked two jobs, his father, Ernesto, said.
The prosecutor's office of Suffolk County has not identified any suspects in this case, according to Jack Wark, a spokesman for Suffolk County District Attorney Daniel Conley.
The investigation by the homicide unit of the Boston police and Suffolk County district attorney is ongoing and "very active," Wark said.
Civil suits may be filed while a criminal investigation is ongoing, but the step is unusual, said CNN legal analyst Paul Callan. Civil and criminal cases, however, have different standards of proof.
The loss of Abreu and Furtado should matter and there is no reason to wait, said attorney William T. Kennedy.
Meanwhile, Hernandez has been moved to a more restrictive jail unit while a fight with another inmate is investigated, Bristol County Sheriff Thomas Hodgson told CNN Thursday. Hodgson said the move wasn't disciplinary but rather standard procedure.
Hernandez has been placed in a higher-level security unit and is allowed out of his cell for one hour a day, the sheriff said. He will not interact with other prisoners and must wear handcuffs and leg shackles.
In January, unsealed court documents revealed that police had directly suggested that the former tight end may have pulled the trigger in the unsolved double homicides.
"There is ... probable cause to believe that Aaron Hernandez was operating the suspect vehicle used in the shooting homicides ... and may have been the shooter," said a recently unsealed warrant from June 2013.
The warrant was used to search a bag of clothes with Hernandez's name on it and a Toyota 4Runner linked to him that, according to court documents, was seen at the scene of the crime by witnesses the night of the killings.
CNN has reported that a grand jury has been looking into whether Hernandez played a role in the drive-by shooting, said law enforcement sources in January.
Hernandez is awaiting trial on murder charges in the 2013 shooting death of his friend Odin Lloyd. He has pleaded not guilty.
Lloyd's family also filed a wrongful death suit against Hernandez in December, according to Kevin Phelan, the family's attorney.
Hernandez is also named in another civil suit.
A man that sources have described as Hernandez's "muscle man," Alexander Bradley, has filed a civil lawsuit accusing Hernandez of shooting him in the face during an argument after they left a Florida strip club in February 2013.
Bradley lost sight in one eye because of the shooting, according to the lawsuit.
CNN's attempts to reach Hernandez's attorney were unsuccessful.
CNN's Susan Candiotti contributed to this report.