The suspects are said to have committed the crime at an incomplete building in Huruma estate along the Eldoret-Webuye highway.
Police from the Directorate of Criminal Investigations unit are still pursuing the other two suspects who have gone into hiding.
A courtroom in Eldoret was moved to tears on Tuesday as a woman recounted the harrowing moment three men allegedly used a mandazi to lure her mentally challenged granddaughter before gang raping her.
The grandmother described how the suspects took turns assaulting her granddaughter after trapping her with the snack, painting a chilling picture of predators preying on the most vulnerable.