A group of United Nations human rights experts on Friday expressed "legitimate concerns" over the decisions to not bring the cases of Michael Brown and Eric Garner, two black men who were extrajudicially killed by police in separate incidents, to trial.

"I am concerned by the grand juries' decisions and the apparent conflicting evidence that exists relating to both incidents," Rita Izsák, U.N. Special Rapporteur on minority issues, said.

"A trial process would ensure that all the evidence is considered in detail and that justice can take its proper course," Izsák continued. "The decisions leave many with legitimate concerns relating to a pattern of impunity when the victims of excessive use of force come from African-American or other minority communities".

The statement comes in the same week a Staten Island grand jury decided to not bring the case of Eric Garner, a black man who died after police put him in a choke hold, to trial. In late November, a similar decision was made in the case of Michael Brown by the St. Louis County grand jury. The unarmed teen was shot and killed by a police officer in Ferguson, Missouri.

Protests erupted across the nation following both decisions.

The U.N. Special Rapporteur on contemporary forms of racism, Mutuma Ruteere, highlighted the "continuing evidence of discriminatory practices including racial profiling by police officers targeting African Americans as specific challenges requiring urgent action" on Friday.

Ruteere cited evidence of blacks being disproportionately targeted by police who often resort to using force.

Another U.N. human rights expert, Mireille Fanon Mendes France, called for the expedited investigations of the two cases, saying, "The Michael Brown and Eric Garner's cases have added to our existing concerns over the longstanding prevalence of racial discrimination faced by African-Americans, particularly in relation to access to justice and discriminatory police practices."

"We call for finalization without undue delay of the ongoing investigations into the cases, the delivery of justice and reparations for the victims concerned," she said. "We urge a comprehensive examination of all laws that could have discriminatory impact on African-Americans to ensure that such laws are in full compliance with the country's international legal obligations and relevant international standards."

U.S. Attorney General Eric Holder has launched a Justice Department investigation into the murder of both men.

"All lives must be valued," Holder said on Wednesday while announcing that his department would conduct an investigation into the death of Eric Garner. "Mr. Garner's death is one of several recent incidents across the country that have tested the sense of trust that must exist between law enforcement and the communities they are charged to serve and protect. This is not a New York issue or a Ferguson issue alone. Those who have protested peacefully across our great nation following the grand jury's decision in Ferguson have made that clear."