The investigation into Nolan Wells‘ death had several developments this week as his family subpoenaed social media records, hired experts to analyze a July 4 distress call and saw the reward in the case increase to $225,000.

Family expands investigation with audio review

On Thursday, the civil rights attorney Ben Crump spoke at the National Urban League Conference and said Wells’ family has retained audio engineering experts to review a distress call made from a boat on the day the Southwest Mississippi Community College football player disappeared off Mississippi’s Horn Island, according to The Associated Press.

The July 4 recording was released by the Mississippi Department of Marine Resources, capturing someone aboard a boat telling a private Sea Tow dispatcher, “Our bilge pump stopped working. We’re sinking. Can y’all please come?” The dispatcher later says those onboard had resolved the issue and “don’t need any help right now.”

Crump also called for outside authorities to help review the cellphones of the friends who traveled with Wells to Horn Island.

The teen’s parents attended the conference alongside Crump, where his mother, Christine Wonsley, renewed her plea for wanting to know what actually happened to Wells.

“We will not rest until we get answers,” Wonsley said.

The family have faced criticism over the investigation into their son’s death. Crump has defended their efforts, saying they are seeking answers rather than trying to blame anyone, per AP.

“We’re not trying to cast aspersions on anybody, we want the truth. If it was your child, you’d want the same thing,” Crump said.

Wonsley subpoenaed several major social media and technology companies in an effort to obtain records tied to her son’s accounts, according to court documents obtained by ABC News and WLBT.

The subpoenas seek messages, photos, videos and GPS location data from Meta platforms Facebook, Instagram, WhatsApp, as well as TikTok, Snapchat and the family’s safety application Life360. They believe the records could help answer questions surrounding Wells’ death.

The filings come after Wonsley previously told ABC News she believed content had been removed from her son’s phone before it was returned to the family, according to Blavity.

“When we finally got his phone, me and my sister went through the phone. We went in his Snapchat. He had two accounts. Absolutely nothing,” Christine Wonsley said. “It wasn’t even 24 hours, which is how long videos and pictures stay in Snapchat … even my sister was like ‘Yeah, that’s suspicious.’”

Authorities have said the investigation remains ongoing. The official autopsy and toxicology report have not been released, while an independent autopsy commissioned by Wells’ family listed his cause and manner of death as “undetermined pending investigation.” The family called for a second independent autopsy, with the results also undetermined. The new report adds criticism to how local authorities handled the legal and medical investigations into the teen’s death, ABC News and Blavity reported.

Reward in Wells’ investigation increases after new $50,000 pledge

The reward for information leading to an arrest and conviction in Wells’ death also increased this week after Dr. Benjamin Hudson, the father of one of the teens who traveled to Horn Island with Wells, pledged an additional $50,000, according to the Sun Herald.

The latest pledge brings the total reward to $225,000 after previous contributions from the Rev. Al Sharpton and Tyler Perry, both of whom pledged $50,000, and former NFL wide receiver Terrell Owens at $25,000.

“We don’t know what happened,” Hudson said on behalf of himself and his son, per the Sun Herald. “We have been completely transparent from the beginning because we want to know what happened, too.”

Wells and a group of friends traveled on several boats to the barrier island to celebrate the Fourth of July holiday. Wonsley had later reported him missing, and his body was found two days later on July 6, Blavity reported.

Authorities have not announced any arrests, and the investigation into Wells’ death remains ongoing.