The former leader of a militia in the Democratic Republic of Congo (DRC) had his 2012 acquittal upheld Friday over charges of war crimes that date back more than a decade ago. Mathieu Ngudjolo Chui, who was accused of leading the Nationalist Integrationist Front (FNI) during a 2003 massacre that killed more than 200 villagers, was originally acquitted in December 2012 for playing a role in the mass deaths. The International Criminal Court Friday ultimately agreed with that ruling. “The Appeals Chamber by majority confirms the acquittal and rejects the (prosecution’s) appeal,” Judge Sanji Mmasenono Monageng ruled, according to Agence France-Presse.

Ngudjolo Chui was first acquitted Dec. 18, 2012, of three counts of crimes against humanity that included specific charges of murder, rape and sexual slavery, in addition to seven counts of war crimes alleging in part that he used children younger than 15 years old as soldiers and that he also targeted civilians who weren't active fighters in the armed conflict that took place Feb. 24, 2003.

The prosecutors in that case ultimately appealed the acquittal -- the first such acquittal for the ICC, which operates out of The Hague, Netherlands, “to help end impunity for the perpetrators of the most serious crimes of concern to the international community.”

Judge Monageng had critical words Friday for the judges in the first trial for not permitting prosecutors to present information from Ngudjolo Chui’s prison telephone calls into evidence before admitting that it didn't “materially affect the acquittal,” AFP reported. Those first round of judges claimed prosecutors didn't prove Ngudjolo Chui’s had any leadership role in the attack on a Bogoro village in the DRC's northeast Ituri region.

According to the ICC, "The Appeals Chamber found that Trial Chamber II had correctly applied the standard of proof set out in the Rome Statute which states that an accused can be found guilty only if the evidence establishes his guilt 'beyond reasonable doubt”, and that its findings and assessment of the evidence were not unreasonable. It also found that Trial Chamber II took into account the entirety of the evidence submitted by the Prosecutor and assessed its credibility in a reasonable way."

A warrant for the arrest of Ngudjolo Chui, 44, was first issued by the ICC in June 2007 before his trial that took more than four years ended in the acquittal in December 2012. After being acquitted, Ngudjolo Chui remained free for the duration of the second trial.