It's the latest act of violence against the those who provide aid for the people in Darfur. In March, a group from Medecins Sans Frontieres were kidnapped, but they have since been returned.
From this AFP article that we found at Yahoo News, see learn more about the tragedy.
"He was ambushed on Saturday by men who wanted his Thuraya satellite telephone," Mark Simmons, country director for the Fellowship for African Relief, told AFP.
"They came to his home on Monday evening to take the phone, but it wasn't there. The armed men then opened fire on him."
Simmons said the attack took place in west Darfur, near the border with Chad.
"We've been in Sudan for 24 years and this is the first time that one of our workers is killed," he said.
The killing came after Sudanese President Omar al-Beshir, accused by the International Criminal Court of committing war crimes and crimes against humanity in Darfur, expelled 13 foreign relief agencies earlier this month.
Beshir has stepped up his defiance of the West since the ICC issued an arrest warrant for him on March 4, vowing to expel foreign aid groups and to replace them with Sudanese organisations.