Police kill four in firefight as Haiti’s president assassinated

Haiti's president was assassinated at his home by gunmen who falsely claimed to be DEA agents. The attackers were initially stopped but allowed through by police. The president was killed, and his wife was injured and treated in Florida. Security forces killed four and detained two mercenaries. Interim Prime Minister Claude Joseph is currently leading the country.

What actions were taken by Haiti's security forces following the assassination?

Who stated that he was running the country after the assassination?