According to the report, Congolese military colonel Jean de Dieu Mambweni has been arrested but is not yet formally charged with murder.
Catalán was found dead along with Sharp and their Congolese interpreter in March 2017. They had been kidnapped 16 days previously in the conflict-ridden province of Kasaï-Central, where they had gone to investigate reported human rights abuse.
Two months after the murders, a military prosecutor said that the Democratic Republic of the Congo (DRC) had arrested “two insurgents” on murder and terror charges. DRC authorities would ultimately round up nearly two dozen alleged militia members and charge them with being involved in the killings.
Authorities denied any involvement of Congolese soldiers in the killings but NGO groups said it was possible that Congolese forces could have taken part in the kidnapping and murders of the UN personnel.
“Given the implication of Congolese army soldiers in much of the violence, we have serious doubts about the Congolese authorities' ability or willingness to carry out a credible, independent investigation,” Ida Sawyer, Human Rights Watch's Central Africa director, said in May 2017.
In connection with Mambweni’s arrest, a new audio recording was submitted into evidence as proof that Mambweni had met with Catalán and Sharp for lunch two days before they were assassinated. He has previously denied having met with them before the murders.
Catalán, a dual Swedish-Chilean national, was 36 years old at the time of her death. Sharp was 34.