NORWICH – A man charged with manslaughter in the death of his girlfriend’s 16-month-old son appeared in court Friday where investigators revealed that his criminal history included the attempted murder and rape of a three-year-old step-sibling.

Jason Allen Sherman, 24, of 5223 Piety Hill Road, Cincinnatus, is charged with two counts of first-degree manslaughter and one count of second-degree assault. He was arrested Nov. 10, 2006 in connection to the suspicious death of infant Marshall Lee Barber Jr. in the Town of Pitcher.

Police discovered the unresponsive infant in his crib at 109 Loomis Lane at around 7 a.m. He was transported to Lourdes Hospital in Binghamton, but was pronounced dead on arrival by emergency room doctors.

The medical examiner ruled the death a homicide following an autopsy finding the cause of death was from blunt head trauma and asphyxiation. At Friday’s hearing, it was also revealed that the infant had suffered abdominal injuries and had a healed fractured arm. The report also noted unexplained injuries to the infant’s groin area.

During the proceedings, the District Attorney’s Office called Chenango County Sheriff’s Lt. James E. Lloyd to the stand. Lloyd said Sherman had been previously sent to a juvenile detention facility for sexual assaulting his 3-year-old stepsister and nearly beating her to death. The crime took place in Louisiana and the specifics regarding the date of the conviction were not given in court. Lloyd said Sherman had attacked the victim while he was supposed to be babysitting her and that the parents of the child were originally arrested, but Sherman eventually stepped forward over the incident.