Mr Kossay was arrested in connection with a protest in front of the State Palace on 28 August 2019 where West Pauan Morning Star flags were flying. He was arrested on 30 August 2019 at his rented home in Depok, West Java. No arrest warrant was shown and during the arrest a gun was pointed at the Papuan students by an officer of the Jakarta Regional Police.

Mr. Kossay is a West Papuan student activist who was one of the Jakarta six political prisoners whose trials were concluded on 24 April 2020. He along with four other prisoners received a 10 month jail sentence which includes time already served while in custody. He will be released in early June. 

He was released on 27 May 2020 after serving a 9 month jail sentence.