The 21-year-old son of a Utah doctor found guilty of murder in the 2011 death of his cancer researcher ex-wife has spoken out about how he fought for three years for his father to be convicted. Salt Lake City pediatrician John Brickman Wall, 51, was convicted of killing Uta von Schwedler in September 2011 amid a bitter custody dispute. He faces up to life in prison. The case was highly contentious, with prosecutors alleging Wall had murdered his wife while defense attorneys claimed von Schwedler killed herself. Their son, Pelle Wall, said that though his father told him and his three siblings that their mother had killed herself, he didn't believe it. Scroll down for video . Pelle Wall, 21, publicly believed his Salt Lake City pediatrician father, John Wall, was guilty of murdering his mother, Uta von Schwedler in 2011 . After spending his entire inheritance from his mother on a campaign to convict his father, Pelle wants a confession. 'As I thought about... my dad's behavior before and after her death, it became more and more apparent to me that - that he was responsible for killing her,' Pelle told CBS's 48 Hours. Prosecutors alleged Wall attacked 49-year-old Uta von Schwedler with a knife, dosed her with an anti-anxiety drug Xanax and drowned her in her bathtub. Defense attorneys countered that the theory was unbelievable, and it was more likely von Schwedler killed herself. Her death initially was treated as a suicide. But family and friends pushed for more investigation, saying the researcher showed no signs of wanting to end her life. Pelle told CBS that he feared for his and his sibling's lives, worrying that they might be living with a murder. 'Part of the reason I was concerned for my safety as well as my sibling's safety - was that I saw this anger that he had towards my mother,' Pelle said. 'It didn't die with her. It jumped and it expanded.' The couple's oldest son, Pelle Wall (left) had testified at the trial claiming that his father was acting bizarre after the family learned von Schwedler had died. John Wall (right) was found guilty of murdering his ex-wife in March . Uta Von Schwedler's body was found in an overflowing bathtub in September 2011 and her death was initially ruled a suicide but further investigation led to the conviction of her ex-husband John Brickman Wall . Salt Lake City officials made no effort to remove the children from Wall's home and the investigation was put on hold. On the day before his 18th birthday in January 2012, Pelle moved out of his father's house into the home of his best friend, Jessica Oglesby, and was welcomed by her parents with open arms. But he had left his siblings behind. 'I realized that my presence there was not protecting my siblings,' he told CBS, adding that his father was upset that he had moved out. 'And once I had that realization and I moved out, then I could take active steps to protect them.' Pelle then fought for custody of his siblings and eventually won. The children were all moved into homes of family friends. His father sued him for a number of family scrapbooks that had been treasured items within the family. One of the books had been found next to von Schwedler's body. Pelle countered his father's lawsuit with a wrongful death suit, holding his father responsible in the death of his mother. Wall was eventually arrested and put on trial for the murder of von Schwedler. The evidence in the case was unusual: A medical examiner thought the shallow cuts on von Schwedler's wrists and leg looked like she was defending herself from an attack, but he couldn't explain the fatal level of Xanax in her system. Forensic experts had very different interpretations of the scene. Pelle Wall (left) spent his entire inheritance from his mother (right) campaigning for his father's conviction. He said now he wants a confession from his father . For the prosecution, spilled antihistamine pills on the floor, a house in disarray and bloodstains in von Schwedler's bed showed she was attacked. The defense said the home revealed signs of a troubled woman who died trying to calm herself with medication. 'The state just can't throw up a whole bunch of theories,' John Wall's lawyer Fred Metos said during closing arguments Thursday. He added self-injury is a rare side effect of Xanax. Prosecutors said von Schwedler studied childhood leukemia and recently made a discovery that could help find new treatments for the disease. She had no prescription for Xanax, but John Wall filled a large one for his mother months before his ex-wife's death. 'He resented her efforts to see the children, to talk with the children, to text the children, to email the children,' prosecutor Nick D'Alesandro said during closings. 'He just couldn't stop talking about how much he hated her.' The night of their mother's death, the former couple's four children were staying at John Wall's house. The next morning, he wasn't at home when they woke up. Instead, he went to a car wash and had the interior of his car cleaned, including a pinkish stain, according to prosecutors. Von Schwedler was a Cancer researcher who studied childhood leukemia and recently made a discovery that could help find new treatments for the disease . He came to work with a scratch on his face and injury to his eye; he said the family dog scratched him while he slept. Police knocked on John Wall's door that night, hours after von Schwedler's boyfriend found her body. During an intense interrogation, John Wall denied having anything to do with her death. The couple's oldest daughter, 19-year-old Malkie Wall, testified that her father returned home deeply troubled and asking his children if he was a monster. His lawyers said he broke down after police made him question his sanity, but there's no proof he was in von Schwedler's house. The jury of three women and five men deliberated for about seven hours before reaching a guilty verdict. After the verdict was read, the Pelle thanked police for years of investigation and 'uncommon persistence. He spoke at the courthouse in Salt Lake City surrounded by more than two dozen supporters. 'We have spent the last three and half years seeking justice for my mother, and today that quest is finally at an end,' he said. The victim's sister, Almut von Schwedler, said the Wall children will never be the same, but the verdict is the first step toward closure. 'Johnny never succeeded to destroy Uta's joy for life, but he ended up taking her life,' she said. John Wall, pictured last year awaiting his trial, faces up to life in prison for the murder of his ex-wife. A sentencing hearing will take place in July . John Brickman Wall, center, listens to blood pattern expert Rod Englert testify for the prosecution with his defense team Jeremy Delicino, left, and Fred Metos in February . 'Revenge was certainly not what drove us in those dark days, and dark and desperate days we had many of,' she added. Prosecutor Matthew Janzen said Pelle Wall played an important part in the case, one of many pieces that formed the largely circumstantial case. As the verdict was read, John Wall sat with his hands folded and shoulders bent, staring down and blinking rapidly as his frown deepened. The defendant's sister, Wendy Wall, maintained her brother's innocence. 'This verdict will not bring Uta back,' she said in a statement. 'Now, to that tragedy has been added the conviction of an innocent man.' Though Pelle has no regrets in fighting for his father's conviction, Wendy Wall is disappointed with what Pelle has done to his father. 'I think that Johnny felt devastated when, you know, when Pelle - in some ways you could say turned on him, I suppose,' she said. 'Everybody in our family Johnny included still very much loves Pelle, and I think that we're all trying to remember that… he's gone through incredible trauma.' Wall will be sentenced on July 8. Pelle said that he expects he will speak to his father 'once he's in prison'. 'I mean, I think I can ask him the questions. But, I don't expect that he'll answer. He'll just, you know, shake his head... and, basically, maintain the victim stance that he's always maintained,' he said.
Pelle Wall spent his inheritance from his mother on a campaign to get his father, John Brickman Wall, convicted . The Salt Lake City pediatrician Wall, 51, was convicted of killing his ex-wife Uta von Schwedler, 49, on in March and faces life in prison . Prosecutors alleged Wall attacked von Schwedler with a knife, dosed her with an anti-anxiety drug Xanax and drowned her in her bathtub . Defense attorneys countered that the theory was unbelievable, and it was more likely von Schwedler killed herself . Her death initially was treated as a suicide but family and friends pushed for more investigation .