Police Constable Titus Ngamau Musila, alias Katitu, was released after staying in custody two years.
Musila, alias Katitu, has been hailed by residents as a vigilante crime fighter who made them safer.
His arrest sparked a mirage of protests from Githurai residents that lasted for days
He allegedly killed Kenneth Kimani and Oscar Muchoki in September 2014.
He has been in remand since his arrest that month.