How serial killer Dorothea Puente got away with murdering Ruth Monroe

Serial killer Dorothea Puente ran a boarding house in the late 1980s that housed homeless and mentally ill people. She got them to sign over their social security checks to her in exchange for room and board and then systematically drugged, killed them, and buried them in her backyard. Since no one ever checked on most of her victims she was able to kill them and still collect their checks. Before she embarked on this deadly scheme, Dorothea had gotten away with murdering her friend Ruth Monroe.

Ruth Monroe met Dorothea Puente at the Flame Club bar where she went with her boyfriend Harold. Dorothea was working there as a part-time cook and became fast friends with Ruth. Soon she met Ruth’s family, including her son Bill, who she asked to call her Grandma.

Ruth had a little bit of money from working at a pharmacy, and Dorothea asked her to invest in a restaurant together. However, the restaurant struggled so Dorothea would ask for more and more money to keep the restaurant open. Eventually, Ruth’s boyfriend Harold got cancer and died. Ruth didn’t want to live alone, so she moved in with Dorothea in April 1982.

Bill would often stop by to see his mom Ruth after work and everything went well with her new living arrangement except for the last three days of her life. He noticed she suddenly started drinking Creme du Menthe despite not being a drinker. She told her son that Dorothea had made her a drink to “calm her nerves” over the failure of their restaurant and the loss of her money.

When Ruth’s son visited the next day his mother was so sick she was in bed. He asked to go check on her, but Dorothea tried to convince him not to go. When he went in to check on her, she didn’t say anything but her eyes were full of tears. He told her she would be okay because Dorothea would take care of her. At the time they believed that Dorothea had a medical background and could give Ruth the medical help she needed. They had no idea she was an expert, but her expertise didn’t lay in healing, but in poisoning.

Ruth’s son didn’t get to visit a third time. By the next day she was dead. Dorothea claimed that her roommate killed herself and toxicology reports revealed that she had deadly levels of acetaminophen, codeine, and meprobamate in her bloodstream.

It was Mike Wood’s last day in the district attorney’s office. He turned the case over to their major crimes unit. At the time, in 1982, they didn’t have a way to prove that Ruth Monroe had not killed herself. Her son, however, is convinced that his mother didn’t commit suicide, but was instead murdered by Dorothea Puente.

Several weeks after Ruth’s death, a 74-year-old man named Malcolm McKenzie claimed Dorothea had drugged him and then stole from him. She was convicted of three theft charges and sentenced to five years in prison. She only served three of those years and by the time she got out she had a new plot cooked up to murder and steal from people once she got out of jail: set up a boarding house for the disadvantaged.

The story of Dorothea Puente is featured on Episode 1, Season 1 of Netflix’s new show Worst Roommate Ever