Dallas - A Texas jury has found a neurosurgeon guilty of maiming patients who had turned to him for surgery to resolve debilitating injuries.The verdict of the Dallas County jury on a first-degree felony charge of injury to an elderly person means 44-year-old Christopher Duntsch of Plano could be sentenced to five to 99 years or life in prison. He also could be given probation. The Dallas Morning News reports the jury deliberated about four hours before deciding on its verdict. The indictment accused Duntsch of wide-ranging malpractice that included improper placement of screws and plates along patients' spines, a sponge left in another patient and a major vein cut in another. Records also showed that he operated on the wrong part of a patient's spine, damaged nerves and left one woman with chronic pain and dependent on a wheelchair.Prosecutors had accused Duntsch of maiming four patients and causing the death of at least two between July 2012 and June 2013. They say Duntsch's hands and surgical tools amounted to "deadly weapons" contended that Duntsch "intentionally, knowingly and recklessly" harmed up to 15 of his patients.Prosecutors said Duntsch said in a 2011 email to his girlfriend that he would "become a cold-blooded killer."But Duntsch's attorneys argued that Duntsch was not a criminal but just a lousy surgeon committing malpractice in chaotic operating rooms in hospitals in Dallas and its northern suburbs. They also said the tone of the email to his girlfriend was unclear could have been meant as sarcasm.