The mother of Tamir Rice, the 12-year-old boy who was killed by police while playing with a toy gun at a Cleveland playground, said she is "looking for a conviction for both of the officers,"

In an exclusive interview with ABC News, Samaria Rice revealed that her daughter, 14, was tackled by police when she arrived at the playground after the shooting.

"I couldn't believe they tackled her, and put her in handcuffs and in the back of the same police car that was on the grass that the officer got out of and shot her brother. So my daughter is sitting there looking at her brother on the ground," Rice said.

Rice has already filed a wrongful death lawsuit over her son Tamir's death, but she wants "the police [to] be accountable for what they did to my son."

Benjamin Crump, the attorney who represents the parents of police-slain teen Michael Brown in Ferguson, Missouri, is representing Rice.

"If the Cleveland police is unequipped to deal with children playing with toys and toy guns, then we need to outlaw toy guns in Cleveland so we have no more children getting killed," Crump said.

He added that it is "unimaginable" to kill children playing at the playground with toy guns.

"We have to address this very seriousl," Crump continued.

The New York Daily News reports that Officer Tim Loehmann, 26, who fatally shot Tamir, agreed to resign from the police department in Independence, Ohio in 2012 due to poor performance, but the Cleveland Police Department never reviewed his personnel files before hiring him.

Loehmann's shooting of Tamir will be under grand jury investigation. The Cuyahoga County Prosecutor's Office will present evidence, and the grand jury will decide whether the officer should face charges.

The Justice Department, following a two-year federal investigation, has found that the Cleveland Police Department officers have a pattern of excessive force. The city is working toward a settlement.