Warning: This article contains details about the outcome of an autopsy that readers may find distressing.

The cause and manner of Mississippi teenager Nolan Wells’ death after he went missing earlier this month remain unknown following an independent preliminary autopsy.

The body of Wells, 18, was found in the water near Horn Island two days after he failed to return with friends from a July 4 boat trip there.

The Jackson County Sheriff’s Office said they did not suspect foul play, but Wells’ family requested an independent autopsy to address what they say are “serious and unanswered questions about the circumstances that left Nolan alone on the island and how he died.”

Initial autopsy results show that foul play cannot be ruled out, the family’s lawyer said Wednesday.

Ben Crump said at a news conference that the examination found a red discoloration on the back of the teen’s head, the cause of which has not been determined.

The examiner, forensic pathologist Dr Roger Mitchell, noted there were no skin wounds or skull fractures in the area.

Mitchell, according to Crump, could not determine if there was any bruising on Wells’ body because it was too decomposed, nor could he say whether Wells was conscious or unconscious when he entered the water.

If Wells drowned, determining how he entered the water and whether he was conscious or unconscious when he did is the “crux of the matter,” Crump said.

Mitchell’s autopsy report also indicated that parts of Wells’ throat had been retained after the initial autopsy, which is standard practice if there are any concerns.

“Therefore, this pathologist cannot rule out a neck injury as a contributor to or cause of death,” Crump said.

Mitchell also noted that the original toxicology results had not yet been received.

“We have more questions than answers right now,” said the attorney, who specializes in wrongful death lawsuits.

The results of an initial autopsy performed by the Jackson County coroner have not yet been released. The BBC has contacted them for comment.

Crump and the Wells family have disputed conflicting reports that have emerged since Wells disappeared.

His 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 on the afternoon of July 4.

She said she was upset that her son’s mobile phone and car keys had been found with his friends after they returned from Horn Island and felt “uncomfortable” that police said her son had accidentally drowned.

Crump also questioned this, saying, “This is a kid who knew how to swim.”

“We are hopeful that our local authorities will do what they need to do, because having the preliminary autopsy results and not knowing anything about them is heartbreaking and concerning,” Wonsley said Wednesday. “That’s why we’re here, that’s why we’ve asked for this help.”