Around 3,000 to 4,000 people went on a rampage on August 11 last year, setting ablaze the houses of Pulakeshinagar Congress MLA R Akhanda Srinivasa Murthy and his sister over an alleged inflammatory social media post by his nephew.
The mob also torched Devara Jeevanahalli and Kadugondanahalli police stations over suspicion that the nephew was present there.
Three people were killed in police firing while another person died due to abdominal injuries suffered in the violence.
In the charge sheet, Sampath Raj was charged with hatching a conspiracy for the violence to finish off the MLA politically in connivance with another Congress corporator and some others.
The Corporator and his aide were also arrested. Police had accused Sampath Raj of remaining in touch with the masterminds throughout the widespread arson and violence.