Duterte not only set the murderers free, he now gave back their badges and guns so they could murder again with impunity. Why? Because Duterte fears that these policemen might rat out on him for what they know about his involvement in the Espinosa murder. Remember, it was divulged during the hearings that right after assuming office on June 30, Duterte had Marcos and company reassigned to CIDG8. But when Gen. Dela Rosa relieved them for being implicated by Espinosa in the illegal drug trade and, at the same time, not having the required schooling to be assigned at CIDG, it was Duterte himself who ordered Dela Rosa for their immediate reinstatement. Then just a few weeks after, Espinosa ended up getting murdered by Marcos' group.
Source: Senate of the Philippines