Montgomery County and the Washington, DC, metropolitan region were plagued by a string of vicious sexual assaults and one homicide for almost thirty years. Known to the public and law enforcement as the Potomac River Rapist, the offender operated between 1991 and 1998, leaving a trail of unresolved cases and terror. Thanks to developments in DNA technology and a cooperative cold case investigation, the mystery was ultimately solved in 2019 and Giles Daniel Warrick was apprehended. Later, while awaiting trial, Warrick passed away.
DNA evidence connected the Potomac River Rapist to at least ten sexual assaults and one killing. Several jurisdictions, including Montgomery County, Maryland, and Washington, DC, were involved in the crimes. Women between the ages of 18 and 58 were the victims. There was a common pattern to the attacks: the attacker would frequently cut phone lines, break into houses, and cover the victims’ heads with a pillowcase or blanket. In certain instances, the victims were attacked in front of their small children. According to the FBI, the occurrences are listed below:
First incident: Monday, May 6, 1991, from 8 to 11 p.m. The woman, 32, was attacked inside her house in Gaithersburg, Maryland’s Washingtonian Woods neighborhood as she was returning from a business trip.
Incident 2: Between 10 and 10:30 p.m. on Thursday, September 5, 1991. In Germantown, Maryland’s Watkins Meadows neighborhood, an 18-year-old babysitter was attacked inside a house.
Third incident: Thursday, November 21, 1991, between 9 to 10 p.m. In the downtown district of Potomac, Maryland, and in the vicinity of Potomac Village, a 41-year-old woman was attacked at her residence.
Incident 4: Between 8:30 and 9 p.m. on Wednesday, December 11, 1991. When she was attacked, a 36-year-old woman and her small children were at home in the Quince Orchard Knolls neighborhood of North Potomac, Maryland.
Incident 5: Around 9 p.m. on Friday, January 24, 1992. In the Potomac Grove neighborhood of North Potomac, a 34-year-old live-in cleaner was attacked at the residence of her employer.
Incident 6: 7-8 p.m. on Tuesday, March 8, 1994. A 35-year-old lady was attacked when she and her small children were at home in the Highwood neighborhood of Rockville, Maryland.
Incident 7: A 58-year-old victim was attacked while out on a stroll in the Palisades district of Washington, D.C., on Saturday, July 20, 1996, between 8:30 and 8:45 p.m.
Incident 8: 7-8 p.m. on Wednesday, February 26, 1997. When a 19-year-old lady returned home from work, she was attacked at her house in the Rock Creek Manor section in Rockville.
Incident 9: 7:30–8 p.m. on Friday, November 14, 1997. After going grocery shopping, a 30-year-old lady was attacked in her Silver Spring, Maryland, home near New Hampshire Avenue and Route 198.
Incident 10: 10:30–11 p.m. on Saturday, August 1, 1998. A 29-year-old intern named Christine Mirzayan was attacked and killed in the 3600 block of Canal Road as she was making her way to her home in the Georgetown neighborhood of Washington, DC.
Christine Mirzayan’s murder is the last and bloodiest crime that has been linked to the serial killer. The 29-year-old intern was slain by being bludgeoned with a heavy rock on August 1, 1998, while she was walking home in the Georgetown section of Washington, DC, after being pulled into the woods and subjected to sexual assault. Although the police investigation was stepped up in response to this horrible crime, the case was unsolved for many years.
Although the name of the perpetrator remained unknown, the case continued to be a major priority for law enforcement for more than 20 years. The FBI started a new public effort in 2011 to get tips, but a big breakthrough didn’t come until a new kind of DNA analysis was employed. A possible culprit was identified in 2019 by Parabon NanoLabs, a forensic genealogy firm.
Investigators concentrated on Giles Daniel Warrick, a 60-year-old resident of Conway, South Carolina, in light of this new information. Warrick was familiar with the neighborhoods where the attacks took place because he had been a landscaper in the Washington, DC, region at the time of the crimes. Warrick was taken into custody and charged with the rapes and murders on November 13, 2019.
On November 19, 2022, Warrick was discovered dead in his cell at the DC Central Detention Facility as he was awaiting trial for the crimes. Authorities think he committed suicide. After years of uncertainty, the victims and their families were able to find some closure with the capture and identification of the Potomac River Rapist, even though his death ended the legal procedures.
The Montgomery County Police Department issued the following press statement announcing Giles Daniel Warrick’s arrest:
Giles Daniel Warrick, 60, of Conway, South Carolina, has been arrested by detectives from the Montgomery County Department of Police’s Major Crimes Division’s Cold Case Unit for a series of sexual assaults that took place between 1991 and 1998.
Yesterday, November 13, 2019, Warrick was arrested in Horry County, South Carolina, based on an arrest warrant. At least eight sexual attacks in Montgomery County, Maryland, and two sexual assaults in Washington, DC, including one that led to a homicide, were committed by Warrick, who was identified as the Potomac River Rapist.
Over nearly thirty years, the Montgomery County Department of Police, the Metropolitan Police Department, and the Federal Bureau of Investigation worked together to make this arrest. We appreciate the help with the arrest from the Horry County Police Department and the U.S. Marshals Fugitive Task Force.
In Montgomery County, Warrick was responsible for a series of sexual attacks in which he would cut off phone lines, break into residences, cover the victims’ heads, and then sexually abuse them. These incidents took place in Montgomery County, Maryland, between 1991 and 1998.
In accordance with Article 27, Section 462 of the Annotated Code of Maryland, Giles Daniel Warrick was charged with six (6) counts of First Degree Rape based on the results of the inquiry. On November 13, 2019, Warrick was taken into custody at his home in Horry County, South Carolina, located on the 200 block of Oak Log Lake Road.
Given the length of time that has passed since Giles Daniel Warrick’s death, detectives are worried that there might be other victims in the region. We ask that anyone with more information call the Major Crimes Division at 240-773-5070.
For inquiries on Giles Daniel Warrick’s murder and the events that took place in Washington, DC, contact the Office of Communications at the Metropolitan Police Department at 201-727-4383.
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