In 1962, Boston Record American reporter Loretta McLaughlin investigates three cases of older women who were raped and murdered by strangulation in the Boston area. She confirms the victims all had stockings tied around their necks in a bow, probably connecting the crimes to a serial killer. The story angers Boston law enforcement as well as Loretta's boss, who plans to kill the report to protect the company.When a fourth victim is found, Loretta and fellow reporter Jean Cole decide to continue the investigation. The two women endure rampant sexism in their workplace and society. Loretta's marriage is strained by her long hours and her family is harassed. While writing the articles, Loretta coins the name "the Boston Strangler".One year later, a seventh woman named Sophie Clark is murdered. A neighbor encountered a man who could be the killer and she provides a vague description. Sophie is much younger than previous victims, which breaks the Strangler's pattern. Loretta and Jean later discover that the Boston Police Department is botching the investigation and not sharing information with other cities. Similar murders, like one committed in New York City by a man named Paul Dempsey, have been overlooked.Albert DeSalvo, a suspect in the investigation, is taken into custody. Sophie's neighbor is asked to identify him in a line-up but she picks a different man, George Nassar. Despite this, in 1964, DeSalvo confesses to all 13 murders. Police do not have enough evidence to tie him to the murders, so he is instead convicted for earlier crimes of robbery and sexual offenses and sentenced to life imprisonment.By 1965, Loretta learns from a police detective in Ann Arbor, Michigan, that there have been six murders there that are identical to the Boston Strangler's work. She travels to Ann Arbor and learns the most likely suspect is Daniel Marsh, an ex-boyfriend of a Strangler victim. Marsh is later arrested but refuses to cooperate with police. In 1973, DeSalvo calls Loretta and tells her to come to visiting hours the next day to hear his side of the story. Before Loretta can meet with him, he is stabbed to death by another prisoner.Following an anonymous tip, Loretta meets with Harrison, a former patient at Bridgewater State Hospital. He reveals that DeSalvo, Marsh and Nassar were all held in the same ward at the same time. Harrison also claims DeSalvo's confession was coached by Marsh and Nassar. Loretta visits Nassar in prison. He denies that he and Marsh coached DeSalvo but admits he hoped to claim the reward. He accuses Loretta and the media of creating a sensation around the Strangler and insinuates that there is more than one murderer but that the public does not want to come to terms with it.Loretta and Jean create a theory that Paul Dempsey killed the first six older women in Boston before he moved to New York. Once Dempsey left Boston, copycat murders arose, resulting in the later victims being much younger. DeSalvo confessed to all 13 murders so Nassar could collect a $10,000 reward per victim. In return, Nassar arranged for DeSalvo to be represented by high-profile lawyer F. Lee Bailey. DeSalvo was also deceived into believing he would get a million-dollar book deal that could support his family. The Record American publishes Loretta and Jean's theory.An epilogue tells of Loretta becoming an award-winning medical reporter at The Boston Globe. Jean continued working as a reporter for 30 years. She and Loretta remained close friends. Marsh was never charged with murder. Nassar never received a reward and is incorrectly said to still be in prison as of 2023.[a] In 2013, DNA evidence linked DeSalvo to the 13th murder but not the other 12