Marlon Michael Alexander was charged on September 14, 2018, for the home invasion sexual assaults of four women that took place between 2007 and 2010 in Germantown and Gaithersburg, Maryland.
His first victim was a 25-year-old woman in Gaithersburg. She is reported to have been a police officer, and she was able to fight off her attacker. This may be why the subsequent victims were all elderly women. One woman was attacked in her home twice, first on 19 June 2010 and then again on 5 January 2011. On August 21, 2010, an 86-year-old woman was raped at a senior living center. The victims were threatened, and the attacker used a weapon. The cases were linked together through semen recovered from the crime scenes.
The FGG investigation was performed by Parabon Nanolabs. The confirmation was made after police obtained warrant to take a DNA sample from Alexander.
Alexander pled guilty to these offences in May of 2019 and has been sentenced to life in prison.
Broom, Scott. “Genealogy Database Tightens Privacy Rules After Helping Catch Montgomery County Serial Rapist.” WUSA 9 News, May 21, 2019. Accessed December 10, 2020. https://www.wusa9.com/article/news/local/maryland/genealogy-database-tightens-privacy-rules-after-helping-catch-montgomery-county-serial-rapist/65-56c0acb8-a3e6-4497-ba13-ffa674cb093b.
Collins, Pat, and NBC Washington Staff. “Montgomery County Rapist Who Targeted Elderly Sentenced to Life in Prison.” NBC 4 News Washington, May 21, 2019. Accessed December 10, 2020. https://www.nbcwashington.com/news/local/montgomery-county-rapist-who-targeted-elderly-sentenced-to-life-in-prison/159940/.
DiGangi, Diana, and Brad Bell. “Life in Prison for Man Convicted of Raping Two Elderly Women in Maryland.” WJLA News, May 21, 2019. Accessed December 10, 2020. https://wjla.com/news/local/life-in-prison-for-man-convicted-of-raping-two-elderly-women-in-maryland.
Moore, Jack, and Mike Morillo. “Police ID Montgomery Co. Cold Case Rape Suspect Using DNA, Online Genealogy Sites.” WTOP News, September 14, 2018. Accessed December 10, 2020. https://wtop.com/montgomery-county/2018/09/germantown-man-charged-several-cold-case-rapes-including-woman-senior-living-center/.