A number of the detained Colombians received US military training while they were in the Colombian military, the Pentagon told The Washington Post.
Rodolphe Jaar and Joseph Vincent, who suspects in the assassination of Haitian President Jovenel Moise, were reportedly government informants.
The National Association of Haitian Clerks said Monday that 2 of its members have been threatened, French-language newspaper Le Nouvelliste reported.
Gang leaders are calling for an uprising in Haiti. But activists say it's no surprise they'd exploit political turmoil and instability.
Associates suggested to the AP that Christian Sanon was duped into the plot, and wouldn't have been involved in anything that was violent.
A CNN report traced the journey of the suspects in the killing of Jovenel Moïse in the hours after his death, which led to a protracted firefight.
The US Drug Enforcement Administration confirmed to Insider that at least one of the men arrested by Haitian authorities had worked as an informant.
"A transitional government in Haiti is the only way forward. Port-au-Prince is now in complete chaos," an account linked to Christian Sanon tweeted on June 7.
Christian Emmanuel Sanon, a Haitian-born doctor living in Florida, recently flew to Haiti on a private jet with "political objectives," police said.
The motive of Jovenel Moïse's killing remains unclear. Haitian authorities have accused 28 men, most of whom are Colombian, of being part of the hit.
Martine Moïse, who is recovering in a Florida hospital, said the attack happened so quickly her husband was unable to speak.
One of the US citizens arrested in connection with the Haitian president's assassination said he found a job listing to translate for the hit squad.
"He's a good boy, respectful," Schubert Dorisme, a 63-year-old Florida resident, told Insider of his 35-year-old nephew James Solages.
Haitian-American James Solages was arrested alongside more than a dozen other suspects after the killing of President Jovenel Moïse.
James Solages and Joseph Vincent were sitting on the floor with four other suspects at a police press conference about the Haitian president's murder.
"I'm quite a pessimistic guy, but I didn't expect any assassination," a Haitian native and political expert told Insider.
James Solages was among six people arrested in the killing of Haitian President Jovenel Moïse, a Haitian official told news outlets.