Koli was one of the key accused in the Nithari killings, which came to light in Noida in December 2006 after human remains were recovered near House D-5 in Sector 31.
The case involved the disappearance and deaths of several children and a young woman in and around Nithari. Koli, who worked as a domestic helper for businessman Moninder Singh Pandher, was convicted in multiple cases and was initially sentenced to death.
However, the legal case later took a major turn. In October 2023, the Allahabad High Court acquitted Koli and Pandher in the cases before it, citing a lack of evidence. The Supreme Court subsequently dismissed the Uttar Pradesh government’s appeals against several of those acquittals in July 2025.