IGG Cases > Marlon Alexander

Marlon Alexander

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.

Sources:

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/.

Individual

First Name Marlon
Last Name Alexander
Other Names
Victims 4 (Details)
IGG Started nd
Case Cleared 2018-09-14
IGG Org Parabon

Victims

Case ID Name Age Case Opened Location Investigating Org Most Serious Charge Disposition Court
1107 n/a Jane Doe 25 2007-07-31 Gaithersburg, MD Montgomery CPD All sexual offenses, including rape, sexual assault, and child molestation Guilty plea entered by defendant Montgomery CO DIST CT
1110 n/a Jane Doe 68 2010-06-19 Germantown, MD Montgomery CPD All sexual offenses, including rape, sexual assault, and child molestation Guilty plea entered by defendant Montgomery CO DIST CT
1109 n/a Jane Doe 86 2010-08-21 Germantown, MD Montgomery CPD All sexual offenses, including rape, sexual assault, and child molestation Guilty plea entered by defendant Montgomery CO DIST CT
1108 n/a Jane Doe 68 2011-01-05 Germantown, MD Montgomery CPD All sexual offenses, including rape, sexual assault, and child molestation Guilty plea entered by defendant Montgomery CO DIST CT

Last updated: February 9, 2024

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Case data and narrative licensed under CC BY 4.0: Dowdeswell, Tracey (2023), “Forensic Genetic Genealogy Project v. 2022”, Mendeley Data, V1, doi: 10.17632/jcycgvhm96.1. All other content, including photos, have been added.