The medical examiner in Cuyahoga County, Ohio, has ruled that the fatal shooting of 12-year-old Tamir Rice by a rookie Cleveland police officer last month was a homicide, and that the boy died from a gunshot wound just above his navel.

In a report released on Friday, the medical examiner, Dr. Thomas P. Gilson, said he believed Tamir’s death was the “result of a gunshot wound to the abdomen which injured his inferior vena cava, intestines and pelvis.” The inferior vena cava is a large vessel that returns deoxygenated blood from the lower body to the heart. The autopsy found that doctors had performed a surgical procedure that included “a closure of the inferior vena cava proximal to a gunshot injury.”

Tamir was shot about 3:30 p.m. on Nov. 22 after someone called the police to report that he was waving what looked like a gun in a park near his home. Within seconds of arriving, a police officer shot him, but the gun turned out to be a toy used to fire plastic pellets. Tamir was officially pronounced dead at 12:54 a.m. the next day. According to the autopsy, he was 5-foot-7 and 195 pounds and had an appearance “consistent with the reported age of 12 years or older.”

A lawsuit filed by the boy’s family says the rookie officer and his partner “refused to provide any medical attention to Tamir for at least four minutes as he lay on the ground alive and bleeding.” According to Cleveland

.com, Tamir was not given first aid until an F.B.I. agent with medical training showed up, and the police said an emergency medical crew then arrived three minutes later.