HOUSTON --More than three decades after a family buried what they thought were their sons and brothers, the Medical Examiner opened that grave. Eyewitness News was the only crew there to witness the rare proceeding Tuesday morning. It is just the latest horrible twist in the long story of serial killer Dean Corll. For more than 30 years, the skeleton of a teenage boy was waiting just a few feet underground to tell us about a tragic mistake. Today with the help of a backhoe and modern science, the secret is finally coming out. Two victims of Dean Corll, a notorious Houston serial killer, are buried in a shared grave in a west Houston cemetery. The Baulch family thought the bones were Michael and Billy Baulch - brothers killed in the early 70s. But 37 years after their bones were found, anthropologist Dr. Sharon Derrick realized a tragic mistake was made. "It's all so sad. We look at it as an interesting scientific case, but we can also separate that out and look at the trauma the families went through and that they're still going through," said Dr. Sharon Derrick of the Harris County Institute of Forensic Science. Dean Corll and his accomplices lured teenage boys, mostly from the Houston Heights area, to his home for parties. After drinking and using drugs together, Corll bound, tortured and killed his victims. He buried most of the bodies in a South Houston boathouse. Corll was killed by one of his accomplices who then helped police find the 28 victims. "This office worked 24 hours a day trying to make these IDs," said Dr. Derrick. But so many of them were just bones and the 1970s-era identifications lacked the ability to check DNA. Once the old bones were analyzed with new science, Dr. Derrick realized the supposed brothers buried together weren't brothers at all, but a tragic mingling of two teenagers connected only by a gruesome killer. Righting the decades-old wrong brought Dr. Derrick to Woodlawn Cemetery in west Houston Tuesday to unearth the casket with two sets of remains. One of them is Billy Baulch. The other is still unknown to everyone but the now-dead serial killer. Dr. Derrick is already analyzing the unearthed bones to figure out who they belong to and give a family answers they long ago needed. "There is a family out there who never knew what happened to their teenage son, brother -- and all these years, I'm sure they're still wondering," said Dr. Derrick. It will take months to work up a biological profile of the unidentified remains and try to match it with a few of the missing persons reports still remaining from the 1970s. They hope they can complete the circle and tell a family what happened to that young boy. The remains of the second Baulch brother were found years ago and are now buried in another cemetery on the north side of town.