Tamir Rice's death ruled homicide

• Tamir Rice, 12, was shot when, police say, he reached for a toy gun in his waistband last month


• Police: Boy pointed the gun outside a Cleveland recreation center; it turned out to be air gun


• The boy died from a gunshot wound to his torso, the medical examiner says

(CNN) -- The death of Tamir Rice, a 12-year-old boy who was shot last month by a Cleveland police officer who authorities say mistook the child's air gun for a real firearm, has been ruled a homicide, the Cuyahoga County Medical Examiner's Office said Friday.

The November 22 shooting outside a Cleveland recreation center is under investigation, and Tamir's family has filed a lawsuit against two officers and the city over his death.

The cause of death was a "gunshot wound of the torso with injuries of major vessel, intestines and pelvis," according to paperwork provided by Christopher Harris in the medical examiner's communications office.

A demonstrator in Washington holds a picture of Tamir Rice on December 1 at a protest about a different case: last month's decision by a grand jury not to indict a police officer in the shooting death of Michael Brown in Ferguson, Missouri.

Rice was pointing a pellet gun at people outside the recreation center before he was shot, police say. A witness called 911 to say that a black male -- "probably a juvenile" -- was pointing "a pistol" at people, but added twice that the gun was "probably" fake.

A dispatcher asked officers to respond, but it doesn't appear the dispatcher told them of the caller's suspicions that the gun was probably fake or that the person was probably a minor.

Two officers arrived in a police car. Within two seconds of exiting the car, Officer Timothy Loehmann shot Tamir, and the boy died the next day, police say.

Tamir Rice's teen sister 'tackled' after his shooting, mom says

Police have said that Loehmann opened fire after Tamir reached for the gun in his waistband and that an orange tip indicating the gun was a toy had been removed.

Tamir's mother, Samaria Rice, has said she didn't allow her son to play with toy guns, and one of his friends gave the air gun to him.

Loehmann, 26, and the car's driver, Officer Frank Garmback, 46, are on paid leave as the investigation is conducted.

CNN"s Eliott C. McLaughlin contributed to this report.