Claude Joseph, the acting interim prime minister, has claimed to be in charge
He says he should run the country until elections in September
The president, Jovenal Moise, was murdered on Wednesday by mercenaries
On Monday Moise named Ariel Henry prime minister, but he hasn't taken power
A third man, Senate chief Joseph Lambert, has claimed he should rule Haiti
The constitution is unclear given a series of unpredictable events
Haiti National Police said there were 28 presumed assassins responsible
Of the 28, 17 are arrested; three dead; and eight still at large
The 28 are comprised of 26 Colombians and two Haitian-born American citizens