The International Criminal Court on Monday hears Congolese warlord Bosco Ntaganda to decide whether he should stand trial for murder, rape, sexual slavery and using child soldiers.
The man known as "The Terminator" is the founder of the M23 rebel group Kinshasa eventually defeated late last year, after an 18-month insurgency in the eastern Democratic Republic of Congo's North Kivu region.
But in The Hague he is facing 13 counts of war crimes and five of crimes against humanity over abuses allegedly committed a decade ago when he was a warlord in Ituri, further north.
Prosecutors say at least 800 people were killed by Ntaganda's Patriotic Forces for the Liberation of Congo (FPLC), an ethnic Hema group battling rival Lendu militias for control of the mineral-rich area.
"Ntaganda planned and commanded scores of coordinated military attacks against the Lendu and other non-Hema tribes," prosecutors said in court documents.
Forces under Ntaganda's command "attacked villages with heavy weapons and systematically chased (out) the population... hunting house-to-house and into the bushes, burning all properties and looting," they said.
Ntaganda often visited camps where child soldiers under 15 years were trained and "he took part directly in attacks" with child soldiers.
At his first appearance in March last year, Ntaganda told judges: "I was informed of these crimes and I plead not guilty."
The judges have two months after Monday's hearing to decide whether the case against Ntaganda should proceed to trial.
The first-ever suspect to voluntarily surrender to the ICC, Ntaganda walked into the US embassy in Rwanda's capital Kigali 11 months ago and asked to be sent to The Hague.
Observers said Ntaganda was possibly fearing for his life as a fugitive from a rival faction in the M23 rebel movement, although his motives remain unclear.
The ICC had issued two arrest warrants against Ntaganda -- the first in 2006 and a second with additional charges in 2012.
The Rwandan-born Ntaganda is suspected over attacks on a number of Ituri towns over period of a year starting in September 2002.
Prosecutors accuse Ntaganda of leading the November 2002 attack on the gold mining town of Mongbwalu that lasted six days and left 200 villagers dead.
Born in 1973, Ntaganda is the fifth African in the ICC's custody.
His co-accused at the ICC, former FPLC commander Thomas Lubanga, was sentenced to 14 years in jail in 2012 on similar charges.
Ntaganda had managed to evade arrest after the tribunal's first warrant was issued mainly because he remained a powerful commander.
In 2006, he became a military leader for the CNDP, an ethnic Tutsi rebel group led by Laurent Nkunda.
The insurgency was ended by a peace deal that integrated the ex-rebels into the army. Ntaganda was made a general and began building a parallel command in the military.
He activated that network to form the M23 in 2012 when President Joseph Kabila signalled he was ready to comply with the ICC warrant and have him arrested.
UN and other experts accuse Rwanda of being Ntaganda's master and pulling all the strings in the M23, an allegation Kigali has consistently denied.