The family of Nolan Wells, a Mississippi teenager who was found dead after disappearing last weekend, is demanding answers about what happened to him.

Wells, 18, did not return with friends from a boat trip to Horn Island on July 4 and her body was found in the water two days later.

The Jackson County Sheriff’s Office said “no foul play was suspected” but asked the public to come forward if they have any information.

Civil rights attorney Ben Crump, hired by the family, said there have been conflicting statements from witnesses. He added that he has ordered an independent autopsy to be performed.

An initial autopsy was performed earlier this week, but the results have not been released. Dental records confirmed the body was Wells’, Jackson County Coroner Bruce Lynd told BBC News partner CBS News in the United States.

“The family is concerned that the state of Mississippi is conducting an investigation into the death of a young black man in which young white students may be deemed to bear some culpability,” Crump told ABC News’ Linsey Davis.

Crump has disputed what he says are conflicting reports about whether Wells left Horn Island with friends or stayed behind, and said in a statement that the Wells family also “has serious and unanswered questions about the circumstances that left Nolan alone on the island and how he died.”

Wells’ mother, Christine Wonsley, was the first to raise the alarm that her son, who played football at Southwest Mississippi Community College and was described by his coach as a “happy-go-lucky kid,” had gone missing after he did not return the night of July 4.

Authorities discovered his body off the island’s coast on July 6, after a search that included multiple local, state and federal agencies.

The National Park Service described Horn Island as having “no staff, drinking water, shelter, facilities or communication.”

Christine Wonsley and Nolan’s father, Elmore Wonsley, told CBS Mornings that they do not believe their son would have decided to stay on the island alone.

“That’s not in his character,” Elmore Wonsley said.

The Jackson County Sheriff’s Office issued a news release “asking anyone who was on or near Horn Island on July 4” to contact the department and also requested original, unedited photos and videos of “alleged altercations” or images of Wells.