NEW YORK — The family of Nolan Xavier Wells has flown his body to Washington for an autopsy as part of an independent investigation seeking clarity on how he died off the Mississippi coast.

Appearing at a news conference Friday, Wells’s parents said they have retained civil rights attorney Ben Crump to lead an investigation into Wells’s death over the Fourth of July weekend. The death of the 18-year-old Black man has unnerved civil rights leaders who question whether Mississippi officials have adequately scrutinized the circumstances behind his death.