EL PASO, TX (KTRK) -- New video shows the final moments of an Army combat veteran stationed at Fort Bliss, Texas when he checked into the El Paso County Jail for a two-day DWI sentence in July of 2012.Sgt. James Brown served two tours of combat duty in Iraq and was a decorated soldier, KFOX-TV reports . The 26-year-old was active duty when he was booked for the two day sentence at the county jail.When he checked in, jail records show Brown reported that he'd been diagnosed with post-traumatic stress disorder.The video, obtained by KFOX-TV , then begins showing Brown having some sort of episode in his jail cell. Several officers dressed in riot gear then go into his cell. Brown doesn't appear to offer any resistance as officers hold him down, but you can hear Brown yelling that he can't breath.The video then shows officers carry Brown into another room where they cover his face with a "spit mask," CNN reports . Officers then inject him with two shots of a sedative.Brown is then heard begging for water and telling officers "I've got problems."Officers eventually give him a small amount of water. Brown then collapses to the floor.The video then shows officers carrying Brown, now nude, back to his cell. His breathing is visibly worse than before. Emergency medial officials were then called, 35 minutes after the incident began, but it was too late. KFOX-TV says Brown was declared dead a short time later."When a 26-year-old man checks into jail for a court imposed sentence on a Friday, and he leaves Sunday in a casket, something went horribly wrong there," Brown's family attorney B.J. Crow told KFOX-TV.Details about what exactly caused the detail are still unclear. The Texas attorney general's office only released 20 minutes of the footage to KFOX-TV . The El Paso County Sheriff's Office blames the death on natural causes."Mr. Brown's death was an unfortunate tragedy. The sheriff's office has conducted a thorough review of the facts surrounding Mr. Brown's death and, based upon all the evidence obtained, determined that his death was caused by a pre-existing medical condition. The specific evidence cannot be discussed because of pending litigation," Sheriff Richard Wiles said in a statement to KFOR-TV Brown had no criminal record. The toxicology report showed he had no illegal drugs in his body. His family lawyer believes Brown suffered from a sickle cell crisis, which is a usually dormant condition triggered by dehydration and stress.His family is now suing for damages, claiming police used excessive force and failed to provide proper medical attention."He was bleeding out the ears, the nose, the mouth, his kidney's shut down, his blood pressure dropped to a very dangerous level, and his liver shut down," Crow told KFOX-TV The federal civil case is expected to go to trial this October.