Autopsy results released Thursday revealed that Tyler Schmidt and Sarah Schmidt, both 42, and their six-year-old daughter Lula were shot, stabbed and/or strangled inside their tent at Maquoketa Caves State Park in Jackson County on July 22. the Associated Press reported. Mr Schmidt was shot and stabbed while his wife died from stab wounds. Lula died from a gunshot wound and strangulation. Their deaths have been ruled a homicide, the Iowa Department of Public Safety said in a statement. The couple’s son, nine-year-old Arlo, survived the attack. The alleged killer, 23-year-old Anthony Sherwin of LaVista, Nebraska, died of a self-inflicted gunshot wound. His death has been ruled a suicide. Sherwin was camping with his mother at the park when the murders took place, authorities said. Iowa Department of Public Safety Assistant Director Mitch Mortvedt said the department has “indications of a motive” but would not release that information at this time, NBC reported. A GoFundMe page has been set up by family members for Arlo, who is described as a “strong boy, surrounded by family and friends who support him as best we can.” It is unclear if Arlo was inside the tent at the time of the attack or if he was injured. Adam Morehouse, Ms. Schmidt’s brother, told The Associated Press after the murders that he did not believe Arlo had been attacked. “He’s with family and he’s fine, but I haven’t had any interaction with him,” Mr Morehouse said. “As far as I know, he was not physically injured.” Morehouse also said he believes the attack was a “completely random act.” Officers responded to reports of shots fired at the popular park’s campground just before 6:30 a.m. on July 22, according to the Iowa Department of Criminal Investigation. Sherwin was the only registered camper at the site who was missing, according to police. After searching the area, officers discovered Sherwin’s body. “He was known to be armed. That of course raised our awareness as well,” Mr. Mortvedt told the Des Moines Register.