Michael A. Johnson Jr. was born on September 5, 1985, in South Side, Chicago. He was born with a physical disability, missing three fingers on his right hand. This condition may have been caused by his mother’s heavy drug use during her pregnancy. When Johnson was five years old, his father left the family. He and his six siblings were then taken care of by their mother, who often neglected them.

Johnson's mother had a difficult life and struggled to provide for her children. She frequently beat Johnson and his siblings with electrical cords. She also kept them from leaving the house, and as a result, they were not allowed to go to high school. To make money, Johnson's mother resorted to prostitution. Due to their financial struggles, Johnson often went to the corner store to beg for food.

In 2006, Johnson met Tena Anderson at a friend's birthday party. They started a relationship, and a year later, Anderson had a baby with Johnson. In April 2008, Johnson got a job at FedEx. Unfortunately, he faced financial difficulties, which led to him becoming homeless. He eventually lost his job at FedEx due to these struggles.

A few months after being laid off from work, Michael A. Johnson Jr. met a 43-year-old sex worker at a gas station. He convinced her to go with him to a foreclosed home he once lived in. After they had sex, she refused to perform a specific act he asked for. This angered him, and he attacked her. He choked her until she lost consciousness, then sexually assaulted her. Afterward, he threw her off the second-story balcony and left her in an alley. She survived but had severe injuries.

Two months later, in November 2008, Johnson killed another woman, 38-year-old Eureka Jackson. He strangled her and dumped her body in a boarded-up building in the West Pullman neighborhood. Her body was discovered with her shirt tied around her neck.

In January 2010, Johnson killed 29-year-old Leslie Brown. He strangled her and left her nude body at the intersection of 119th and Wentworth, where it was later found by a passerby.

Later that March, Johnson attacked Candice Franklin. He choked her until she lost consciousness and then raped her but left her alive. She woke up with serious injuries but was able to survive. Johnson also killed 30-year-old Siobhan "Shay" Hampton later that month and discarded her body near Harold's Chicken Shack. In May, he killed his final victim, 29-year-old Lutelda Hudson, also by strangulation.

In May, after recovering from her injuries, Franklin returned to her work as a sex worker. While on the streets, she saw Johnson and recognized him. She ran to her boyfriend’s home, and Johnson followed her but did not enter. A few weeks later, Franklin spotted him again and called her boyfriend, who confronted Johnson. Police arrived quickly and arrested him. DNA evidence linked him to three of the murders. He was charged with four murders and the attempted murder of Franklin.

In March 2014, Johnson was convicted of the attempted murder of Franklin and received a 90-year sentence. The following year, he was sentenced to 100 years for the murder of Brown. He has not yet been tried for the other three murders.