As part of an exclusive interview featuring four mothers mourning lost sons, on Friday Samaria Rice recounted the way in which she learned of her child's death.

"Two more boys came and knocked on my door and said the police just shot your son twice in the stomach," she told Anderson Cooper. "I was still in disbelief until I actually seen my son laying on the ground. And the police was surrounding him."

On Friday, 12-year-old Tamir Rice's death was ruled a homicide.

Watch the above clip, as Samaria Rice explains why she feels video from that day, and audio of Tamir's screaming sister, needs to be seen and heard by the world.

In a CNN exclusive interview, on Friday evening Anderson Cooper welcomed four women, all of whom are mothers grieving for a lost son.

Though the circumstances surrounding the deaths of Michael Brown, Eric Garner, Trayvon Martin, and Tamir Rice were different, there existed one constant: in each case the victim was a black male, and perceived to be a threat.

Asked if things might have been different were her son white, and Sybrina Fulton didn't hesitate:

"It’s an easy question for us, I think absolutely my son’s race and the color of his skin had a lot to do with why he was shot and killed," said Trayvon Martin's mom.

Watch the above clip for more of Fulton's response, as well as the answer from Tamir Rice's mother, Samaria.

Connected by similar tragedies, on Friday the mothers of Michael Brown, Eric Garner, Trayvon Martin, and Tamir Rice found themselves together in one room, all talking with Anderson Cooper.

Each of the four women is grieving over a lost son, and though the specifics in each instance varied, certain similarities did exist. And one of those similarities was race.

"If Eric Garner was a white man, in Suffolk County doing the same thing that he was doing – even if he would have been caught selling cigarettes that day – they would have given him a summons," said Garner's mother, Gwen Carr. "He wouldn’t have lost his life that day. I believe that 100 percent."

Watch the above clip as Trayvon Martin's mother, Sybrina Fulton, explains what she thinks needs to happen for police profiling and racial bias to change.