BRATISLAVA, Slovakia (AP) — Slovakia's police say they have charged a suspect with ordering the slaying of an investigative reporter and his fiancee, a case that brought down the Slovak government.

Police didn't immediately name the suspect, but state prosecutors are planning a news conference later Thursday.

Jan Kuciak and Martina Kusnirova were shot to death in their home on Feb. 21, 2018. Slovak authorities believe it was a contract killing linked to Kuciak's work. He was investigating possible government corruption and ties between politicians and Italian mobsters.

Four suspects have been charged but the mastermind was believed to be still at large.

The killings triggered major street protests and a political crisis that led to the dismissal of the national police chief and the government's collapse.