Majid Salek Mahmoudi was born around 1953 in Tabriz, Iran. He grew up in a large family and struggled with school, dropping out in the fourth grade. His father arranged for him to work in a market, where he learned how to run a business. After completing his mandatory military service, his father passed away, leaving him to find his own way.

Mahmoudi eventually married a teacher and started a decoration company while also working as a taxi driver. At first, his businesses were successful, but over time, he faced serious financial problems and went bankrupt. His troubles worsened when he was sentenced to two years in prison for writing a bad check. When he was released, he discovered that his wife had been unfaithful with his cousin.

Between 1981 and 1985, Mahmoudi committed a series of murders, resulting in the deaths of at least 24 individuals. His first known victims, in 1981, were a 36-year-old woman named Akhtar and her two 11-year-old children, Mohammad and Farahnaz. Subsequent victims included women aged between their mid-20s and mid-50s, discovered in various locations such as Tehran, Varamin, Rasht, Amol, Ardabil, and Takestan. The majority of these victims were strangled or suffocated. ​

An informant suggested that Mahmoudi's criminal behavior escalated after he served a two-year prison sentence for writing a bad check. Upon his release, he discovered his wife had been unfaithful with his cousin. While he did not harm them, he began targeting women he perceived as disloyal. ​

The breakthrough in the investigation came on February 17, 1985, when the body of a 41-year-old woman named Masoumeh was found in Tehran. Witnesses reported seeing her with a slender man driving a green Chevrolet. On February 24, 1985, authorities identified and stopped the vehicle in Tehran's Baharestan Square, leading to Mahmoudi's arrest. A search of his car revealed women's clothing and a one-meter-long white rope hidden in the engine compartment. ​While awaiting trial in Qasr Prison, Mahmoudi died by suicide on May 8, 1986, effectively closing the case.