Bērziņš was greeted at the Rīga Central Prison by his friends, relatives and MP Janīna Kursīte-Pakule. He told Latvian Television that the prison sentence handed to him had been political as he had engaged in "public action".
He was convicted for throwing a brick against the Saeima building but fled Latvia to avoid serving his sentence of one year and eight months, which was regarded as too harsh by some people.
Bērziņš was subsequently arrested in the Czech Republic and extradited to Latvia.
The son of Uldis Bērziņš, the sole living poet included in the Latvian Cultural Canon, Ansis-Ataols enjoyed some public support though his requests for parole were repeatedly denied by the president.
During an online news conference via Skype in July 2016, Bērziņš announced that he felt let down by the Latvian state. As a young boy, he had actively participated in the drive for Latvia's independence but now the Latvian authorities want to put him in jail, he complained.
However, he did not deny that he had been throwing cobblestones at the Latvian parliament building during the 2009 riot, which soon afterwards contributed to the collapse of the government.
On January 13, 2009, a peaceful protest against the government turned into a riot and over 50 rioters have been convicted, although only nine were given real jail terms. The conditional sentence given to Bērziņš by the court became a real jail term after he failed to register with the State Probation Service, which was one of the conditions of his conditional sentence.