Zainab Amin Ansari, a seven-year-old girl living in Kasur, Punjab, Pakistan, went missing on 4 January 2018 while walking to a Quran recitation class. At the time, her parents were in Saudi Arabia performing Umrah, and she was staying with her uncle, Muhammad Adnan, who reported her disappearance to the Kasur District police office. CCTV footage, which the family obtained without assistance from local authorities, showed her walking hand-in-hand with an unidentified bearded man wearing white clothing and a jacket on Peerowala Road. Her body was discovered five days later, on 9 January 2018, at a garbage disposal site on Shahbaz Khan Road near Lahore. An autopsy determined that she had been raped, sodomized, and tortured before being strangled to death.
The case emerged against a backdrop of prior child sexual abuse scandals in Punjab province, where local law enforcement had faced accusations of inaction and cover-up. Following the discovery of Ansari's body, protests erupted across major Pakistani cities, including Islamabad, featuring candlelight vigils, burned vehicles, blockaded roads, and clashes between protesters and police. Two people were killed after breaking into a police station during the unrest, and four police officers were reportedly arrested and investigated for allegedly firing on protesters in Kasur. Public figures, including then-Chief Minister Shehbaz Sharif, Nobel laureate Malala Yousafzai, Imran Khan, and numerous Pakistani celebrities and cricketers, publicly condemned the killing, and the hashtag #JusticeforZainab trended widely.
On 23 January 2018, Shehbaz Sharif announced the arrest of Imran Ali, a 24-year-old mechanic who lived in Ansari's neighborhood. Investigators stated that polygraph testing and DNA evidence linked Ali to the rape and murder of at least eight minor girls in the same area, including Ansari. Ali had reportedly participated in protests following the discovery of Ansari's body. Police also recovered a jacket matching the one worn by the man seen with Ansari in the CCTV footage. Ali confessed to committing the serial rapes and murders.
On 17 February 2018, an anti-terrorism court in Lahore Central Jail convicted Ali of the rape and murder of Ansari and twelve other underage girls. He was sentenced to four counts of the death penalty, one life term, a seven-year jail term, and fines totaling ₨3,200,000. Ali was executed by hanging on 17 October 2018.
The case prompted significant legislative action in Pakistan. In 2020, the country's Parliament passed the Zainab Alert, Response and Recovery Act, 2019 — colloquially known as the Zainab Alert Bill — named in her memory. The law established a mandatory minimum sentence of life imprisonment for those convicted of child abuse and created accountability measures for law enforcement officials who delay investigations into missing-child reports.