July 2020 fire injured dozens of personnel aboard the amphibious assault ship in San Diego
Navy prosecutors have claimed that the Seaman Apprentice grew resentful of the Navy after dropping out of SEAL training and moving to the ship.
His defence lawyers have argued that there is no physical evidence linking their client to the fire, which burned for five days.
The Navy eventually decided to scrap the ship at a cost of $30m, rather than pay between $2.5bn and $3.2bn to repair it, a project that would have taken between five and seven years.
It was one of the worst noncombat incidents suffered by the Navy in recent years, which has lost less than 30 ships to unforeseen circumstances since the end of World War II.
The vessel was undergoing a $250m upgrade at the shipyards in San Diego, when the fire broke out, scattering the 160 sailors and officers who were working on the ship at the time.
More than 60 sailors and civilians suffered minor injuries as well as heat exhaustion and complications from smoke inhalation.
Investigators found that five fire stations on the ship had been tampered with prior to the fire, according to court documents. The ATF, which investigated the claims, determined that the fire began in a section of the ship known as Lower V. They discovered a container which had held a petroleum distillate, which is believed to have been used to start the fire.
Officials within the Naval Criminal Investigative Service began looking into sailors with connections to Lower V, which led them to Mr Mays.
Prosecutors showed an Instagram post made by Mr Mays about a month before the fire showing him standing shirtless inside a Navy vessel, along with the caption “I love the smell of Napalm in the morning,” a reference to Francis Ford Coppola’s film about the Vietnam War, Apocalypse Now.
Another sailor, Seaman Kenji Velasco, also told NCIS agents that he had seen another sailor wearing a mask and carrying a bucket down to Lower V just before the fire. Mr Velasco reportedly told investigators he believed the masked sailor was Mr Mays.
Mr Mays was charged with aggravated arson and the wilful hazarding of a vessel.