MANGALORE: A serial killer known for his alleged modus operandi of using cyanide to kill his victims, was sentenced to death by a court here in three cases of murder.

Mohan Kumar, known as the "cyanide killer", was awarded the death sentence by the fourth additional district and session's court here, which had convicted him on Tuesday last and pronounced the quantum of punishment on Saturday.

Judge BK Naik held Kumar guilty of murdering Leelavathi, a resident of Vamadapadavu, and Anitha (22), a resident of Barimar village of Bantval taluk, and Sunanada of Peruvaje.

Naik observed that "this is the rarest of rare cases" and the convict deserves nothing less than death penalty.

During the hearing, Kumar defended himself saying none of the postmortem reports had mentioned presence of cyanide.

Kumar was arrested on October 21, 2009.The trial of murder cases had commenced in the fast-track court in November 2011, and it was later shifted to fourth additional district and session's court here.