Loyalist protestors blocked the front of the police station in Antrim ahead of the release, while there were reports of disturbances in the loyalist Sandy Row area of south Belfast on Sunday night.
Prosecution lawyers will now decide if charges are to be brought against Adams after his file was sent by the police to the Public Prosecution Service. However, experts say it is unlikely given that police were unable to gather sufficient evidence to charge him after days of interrogation.
PPS lawyers will examine the file and decide if there is enough evidence to bring any charges and what those charges would be.
Adams admitted: “For all I know I could still face charges. I say again, I am innocent of this. This was a grave injustice.
“We can’t bring Mrs McConville back but we can help the family in anyway we can.”