Police in Haiti said Sunday they've arrested a key suspect in the assassination of President Jovenel Moïse who allegedly recruited "Colombian mercenaries" to conduct the operation.

Driving the news: Christian Emmanuel Sanon, 63, who's worked as a doctor in Florida, is the "third Haitian-born suspect with U.S. ties to be arrested" over the July 7 killing, the New York Times notes.

The big picture: The arrest came as top officials from the FBI and Department of Homeland Security arrived in Haiti to discuss how the U.S. could help in the matter, per the Washington Post.

• A Pentagon spokesperson said earlier Sunday the Defense Department was "analyzing" a request by Haitian authorities to send troops to assist in stabilizing the country and protect critical infrastructure.

What's happening: Léon Charles, Hait's national police chief, alleged at a news conference Sunday that Sanon "arrived by private plane in June with political objectives and contacted a private security firm to recruit the people who committed this act" — namely CTU, a Venezuelan security firm based in the U.S., according to the NYT.

• "The initial mission that was given to these assailants was to protect the individual named Emmanuel Sanon but afterwards the mission changed," he added, alleging that the key suspect wanted to become president.
• Police have now taken into custody 18 Colombians and three Haitian Americans, including Sano, over the assassination, Charles said, per Reuters.