NEW YORK (AP) — The family of a Mississippi 18-year-old who was found dead after a July 4 boat trip with friends to an island off the Gulf Coast is expected to call for greater transparency at a news conference Friday with the Rev. Al Sharpton and noted civil rights attorney Ben Crump.Crump, who was retained by the family of Nolan Xavier Wells earlier this week, has said the family has concerns about the investigation and planned to conduct an independent autopsy. Wells travelled by boat to Horn Island, Mississippi on July 4 with a group of friends, but did not make the return trip with them that afternoon. His body was found early Monday morning, more than a day later.While Jackson County Sheriff’s Office officials said investigators don’t suspect foul play in the Black college student’s death, the sheriff has asked for any witnesses or people with video from the popular beach island about 10 miles off the coast of Mississippi to come forward to help shed light on the moments before Wells’ disappearance and death.Family members have raised concerns, saying they’ve seen video of a fight allegedly involving their son, and saying as an elite athlete he was able to swim. Wells, who would have turned 19 next month, attended Southwest Mississippi Community College, where he played wide receiver on the football team.