GALVESTON, TX --His story broke our hearts when we first heard about it. Robbie Middleton was only eight years old when he was doused with gasoline and burned over 99-percent of his body. He died last month. Robert Middleton was severely burned on his birthday back in 1998. We watched his recovery, until he died from cancer related to the burns last month. Robert Middleton's mother told Eyewitness News on Thursday she is thrilled about the new developments that she says will have a drastic affect on the criminal investigation into her son's death. The Montgomery County District Attorney's Office says murder charges are likely against the person believed to have attacked Robert Middleton. That possibility is now bolstered by Robert Middleton's death certificate, which lists homicide as manner of death. For Colleen Middleton, her goal is clear. "I plan to hopefully -- once and for all -- be able to prove who attacked Robert Middleton and for them to be held accountable. That's what I want," she said. Colleen Middleton is now closer than ever to accomplishing that goal. According to the death certificate of her son, Robert Middleton -- who died last month -- the medical examiner lists his manner of death as homicide. A distinction our legal expert says will help establish murder charges. It was 1998, Robert Middleton was tied to a tree, doused with gasoline and burned over 99 percent of his body on this eighth birthday. "I look back on these pictures and I'm like, oh my goodness, how could this kid be smiling through all of this but he did. He always looked on the bright side of things," Colleen Middleton said. She told us there is no doubt in her mind her son is smiling today. A civil lawsuit was filed two years ago naming Don Collins, a former neighbor, as the person who attacked Robert Middleton. A new civil lawsuit is in the works, and as a result, the criminal case is being reopened by the Montgomery County District Attorney's Office, which confirmed to us they charged Collins in 1998 with injury to a child. Collins was 13 at the time. Those charges were later dropped because of insufficient evidence. The Montgomery County attorney is now saying Collins faces the possibility of being charged with murder. Even though Robert Middleton was dying of cancer, he wanted to make a sworn statement. He had to relive the horrible crime. He also relived another equally shocking event. "Where he's told us in this deposition he was sexually molested by Mr. Collins two weeks before the incident at the very location it took place," attorney Craig Sico said. Collins is in prison now on a failure to register as a sex offender in an unrelated case. He was never prosecuted in Robert Middleton's case. Collins refused a request to interview him about the latest developments in this case.