Dr. Khem Singh Gill was involved in a controversy in 1985 when his son, Ranjit Singh Gill, was indicted in the assassination of Lalit Maken and his wife, Geetanjali. Controversy surrounded Maken's alleged involvement in the massacres of Sikhs during the 1984 anti-Sikh genocide in New Delhi. Ranjit was convicted, despite his father's efforts, and sentenced to life imprisonment in 2003. His sentence was later commuted. Ranjit Singh Gill, after the release from incarceration, is involved in community and social development activities.