KD Kempamma, born in the 1960s in Kaggalipura, Karnataka, India, led a life marked by hardship and turmoil. Limited formal education led her to an early marriage with a tailor in Bengaluru, with whom she had three children. In an attempt to improve her family's financial situation, Kempamma started a chit fund business. However, the venture failed, resulting in significant financial losses. This failure, coupled with her involvement in theft, led to her husband's abandonment in 1998.

Following her husband's departure, Kempamma took on various jobs, including domestic work and assisting a goldsmith. During her time with the goldsmith, she became acquainted with the use of cyanide, a substance later central to her crimes. Her experiences during this period, including a six-month imprisonment for theft in 2001, shaped the trajectory of her later actions.

Kempamma's criminal activities escalated to serial murder, with her first known killing occurring on October 19, 1999. She targeted 30-year-old Mamatha Rajan at a temple in Hoskote, Karnataka. Posing as a pious woman offering spiritual guidance, Kempamma lured Mamatha with promises of rituals to alleviate her troubles. She administered cyanide-laced 'holy water,' resulting in Mamatha's death.

Between October and December 2007, Kempamma intensified her killing spree, murdering five more women:

October 10, 2007: Elizabeth, 52, from Satanur, seeking help to find her missing granddaughter, was lured to the Kabalamma temple and poisoned.

December 2007: Yashodhamma, 60, suffering from asthma, was promised relief through rituals at Siddaganga Mutt, Kyata-Sandra, where she was poisoned.

December 2007: Muniyamma, 60, an aspiring devotional singer from Yelahanka, was killed at Yadiyur Siddalingeshwar Temple.

December 2007: Pillamma, 60, a temple priest at Hebbal, was deceived with offers to sponsor a temple arch and poisoned at Maddur Vyadyanathapura.

December 18, 2007: Nagaveni, 30, desiring a child, was lured with promises of fertility rituals and poisoned.

Kempamma's modus operandi involved frequenting temples to identify women in distress. Gaining their trust by posing as a devout woman knowledgeable in rituals, she would invite them to secluded temples, instruct them to wear their best attire and jewelry, and administer cyanide-laced 'holy water' or food during the supposed rituals. After the victims succumbed, she would rob them of their valuables.

Her arrest on December 31, 2007, at a Bengaluru bus stand, came after attempting to sell jewelry belonging to her victims. Upon interrogation, Kempamma confessed to the murders. In March 2009, she was sentenced to death for the murder of Muniyamma, becoming the first woman in Karnataka to receive such a sentence. However, her death sentence was later commuted to life imprisonment.

Kempamma's case has been the subject of various media portrayals, including the book "The Deadly Dozen: India's Most Notorious Serial Killers" by Anirban Bhattacharyya and the Kannada-language film "Cyanide Mallika," released on February 26, 2021.