Sept. 12 (UPI) -- The Department of Justice has decided against bringing federal civil rights charges against the officers involved in the death of Freddie Gray.
Justice Department officials ultimately decided there was not sufficient evidence to meet the burden of proof for federal charges.
"It is not enough to show that the officer made a mistake, acted negligently, acted by accident, or even exercised bad judgment," the DOJ wrote in a released statement. "Although Gray's death is undeniably tragic, the evidence in this case is insufficient to meet these substantial evidentiary requirements."
"The investigation into this incident has been closed without prosecution," the DOJ added.
Gray's death in 2015 while in police custody sparked large protests across Baltimore and the U.S.
On April 12, 2015, Gray, 25, suffered a severe spinal cord injury while being transported in a police van to a booking precinct. Gray fell into a coma as a result of the injury and died a week later.
Six police officers officers involved in Gray's arrest and handling were charged with various crimes, including second-degree depraved murder, by Baltimore State's Attorney Marilyn Mosby. All six officers were acquitted of the various charges in separate bench trials.
Gray's family was awarded $6.4 million in a civil suit filed against Baltimore city officials.
Under the Obama administration, the Justice Department opened an investigation of Baltimore's criminal justice system. The department also opened a civil rights investigation of Gray's death. The latest DOJ decision officially closes the latter investigation.
The broader investigation of the city's police and court system -- concluded last year -- found officers and officials engaged in various forms of racial discrimination, unconstitutional actions and excessive force.
The investigation's findings resulted in a consent decree that ordered Baltimore police and court system to undertake sweeping reforms. In April, a federal judge ratified the decree, defying the wishes of new Attorney General Jeff Sessions and confirming the city's obligation to enact reforms.