Nathuram Godse (1910-1949) assassinated Mahatma Gandhi shooting him three times at point-blank range on January 30th 1948. The assassination came after multiple previous unsuccessful attempts on Gandhi's life. Godse was a committed RSS worker, although to save the organisation in the aftermath of Gandhi's death he denied the connection and the RSS subsequently attempted to disown him.
Godse was close to V. D. Savarkar and a frequent visitor to Savarkar's residence. In his correpondence with Savarkar he wrote, for example: "There is only one leader who is your equal and peer, and that is Dr. Hedgewar [K. B. Hedgewar]". He was also very keen to bring the RSS and the Hindu Mahasabha (then under Savarkar's leadership) on a common platform, and impatient to move the Mahasabha in more radical directions.
References:
• First Terrorist of Independent India, on Kafila.
• The BJP and Nathuram Godse, in Frontline, Jan-Feb 2013.
• RSS involvement and response to Gandhi's killing, on truthofgujarat.com.