Mamikins was born in Leningrad then in the Russian SFSR, and moved to Riga, Latvian SSR with his parents shortly after birth.

[1] Before his election, Mamikins was a journalist working for several Latvian Russian-language newspapers, radio stations and television channels.

Mamikins publicized the incident on social media, making waves in Latvian Russian community.

The visit was condemned by Minister of Foreign Affairs of Latvia Edgars Rinkēvičs[8] and Security Police head Normunds Mežviets.

[12] In 2018, Mamikins left the Harmony party after disagreements with Nils Ušakovs[13] and joined the Latvian Russian Union.