A Congolese military court has sentenced an army colonel to death for taking part in a conspiracy to murder two UN experts in central Congo nearly a decade ago.

At his first trial in 2022, Colonel Jean de Dieu Mambweni received a 10-year term for failing to assist persons in danger and disobeying orders. Military prosecutors appealed, arguing that he bore greater responsibility.

The High Military Court in Kinshasa agreed, finding Mambweni guilty on Friday of the war crime of murder for actively orchestrating the killings, and sentencing him to death, according to a ruling reviewed by Reuters and the sister of one of the victims.

Congo has not carried out an execution since 2003, meaning the sentence will, in practice, become life imprisonment.

What happened?

UN experts Zaida Catalan, a Swedish-Chilean, and Michael Sharp, an American, were investigating mass killings in the Kasai region when fighters from the Kamuina Nsapu militia stopped them on March 12, 2017, at a bridge near the village of Moyo-Musila.

They were marched into the bush and shot. Their bodies were found 16 days later.

The ruling, which closes nearly nine years of proceedings, also upheld death sentences against dozens of militia fighters handed down in 2022.

Prosecutors initially dismissed suggestions that state agents were involved, but later arrested the colonel and other officials, who they said had been working with the rebels.

Catalan's sister, Elizabeth Morseby, welcomed the court's finding that there had been a conspiracy. "This confirms that Zaida and Michael were not simply victims of a random act of violence," she said.