Preliminary findings from an independent autopsy of Nolan Xavier Wells found the 18-year-old died of undetermined causes, his family's attorney announced July 22.
The autopsy, which was conducted by forensic pathologist Dr. Roger Mitchell and paid for by former NFL player Colin Kaepernick, also found Wells' manner of death is undetermined, civil rights attorney Ben Crump said at a news conference.
Wells, a football player at Southwest Mississippi Community College, was reported missing after he did not return from a Fourth of July trip with friends to Mississippi's Horn Island. Authorities recovered his body on July 6.
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The teen's death has garnered widespread attention from public figures like Nancy Grace as Wells' family has raised questions about his disappearance.
Bailey C. Martin, a spokesperson for the Mississippi Department of Public Safety, confirmed in a July 22 statement to USA TODAY that the state medical examiner had completed the initial autopsy on Wells, but said the investigation is "active and ongoing."
"We will not comment on the investigation or the independent autopsy that was conducted," Martin said, urging the public to "allow the investigative process to take its course."
Nolan Wells independent autopsy findings pending further investigation
Wells' cause and manner of death are both undetermined pending further investigation, Mitchell wrote in his report. The independent autopsy was conducted on July 10 after the state medical examiner's initial autopsy, Crump said.
Martin told USA TODAY that the state medical examiner conducted Wells' initial autopsy on July 7 at 8:30 a.m.
"The examination was performed in accordance with the standard procedures and protocols followed for all autopsies conducted by the Office of the State Medical Examiner," Martin said.
In Mitchell's report, among the notable findings was an area of red discoloration on tissue at the back of Wells' head by the occipital bone.
"We actually saw the picture of it. It's significant, you can't help but notice, why is this dark red here in the back of his head?" Crump said.
Mitchell wrote that the cause of death is undetermined, in part, because of the lack of details around the circumstances of Wells' death – like how the teen may have entered the water and how, exactly, his body was found.
Because of the body's decomposition and the fact that an initial autopsy had already been conducted, Mitchell said he was unable to fully examine Wells' airway and stomach. In addition, Mitchell said he did not have Wells' toxicology results, which would be a major factor for his findings.
Mitchell also said in his report that he received Wells' body without portions of the neck and throat. Mitchell said he assumed that these portions of the body were retained by the medical examiner for additional evaluation, which is a common practice.
What we know about Nolan Wells' death
The Jackson County Sheriff's Office has said investigators have not found signs of foul play and its investigation continues. However, speculation around Wells' death has intensified as photos and video allegedly connected to the case have circulated.
Crump has said Wells' family does not accept that the teen could have accidentally drowned given he was a strong swimmer.
Once the sheriff's office concludes its investigation, the case will be handed to Jackson County District Attorney Angel Myers McIlrath and presented to a grand jury. This is a standard procedure for unnatural deaths in Jackson County, not necessarily an indication that a crime was committed or is suspected.
Family remembers Nolan Wells at funeral, $125K reward announced
At a July 20 funeral service for Wells, his mother Christine Wells-Wonsley and his father Elmore Wonsley Sr. described their son as having a "gentle, calming spirit," the Mississippi Clarion Ledger, part of the USA TODAY Network, reported.
"Your absence has left an emptiness that can never truly be filled. A piece of our hearts will always be missing," Christine Wells-Wonsley said. "Nolan, we love you."
The funeral service, which was funded by filmmaker and actor Tyler Perry, drew high-profile attendees including Spike Lee and former NFL star Terrell Owens.
The Rev. Al Sharpton, who officiated the service, announced a $50,000 reward for information leading to an arrest or conviction in Wells' case that he said Perry would match, bringing it up to $100,000. On July 21, Owens said he'll give another $25,000.
Crump urged anyone with information about the case to call 888-991-1772.
Nolan Wells' family questions deleted messages and a filmed argument
Much of the family's unease centers on Wells' cell phone, which his friends had after he went missing, Sharpton said at a July 10 news conference.
When it was returned, Wells-Wonsley said recent Snapchat activity appeared to have been erased faster than the app's normal expiration window.
The family is also aware of a recorded argument on the island involving Wells shortly before he went missing, Sharpton and Crump said July 10. One of Wells' friends who was with him that day, Tracestin Shepherd, disputed that Wells appeared in the video in comments to ABC News.
Crump said the family has concerns about whether Mississippi authorities can provide what they view as a fair and transparent investigation during a July 10 news conference. Sharpton called for a "full and thorough investigation" at the funeral.
Contributing: Anthony Thompson, Pam Dankins, Bonnie Bolden, N'dea Yancey-Bragg
This article originally appeared on USA TODAY: Nolan Wells' family releases independent autopsy results