Montgomery County police are trying to solve three decades-old crimes with a computer-generated composite based on DNA left at two of the three scenes.
Detectives from the department's Cold Case Squad released the image of a man suspected of rape, sexual assault and murder based on DNA from Rockville crime scenes dating back to 1989.
Police believe three crimes in 1989 and 1994 were committed by the same man:
- On June 25, 1989, at approximately 10:15 p.m., a 52-year-old woman was walking on Lewis Avenue in Rockville when the suspect approached her from behind, assaulted her, and then raped her. DNA evidence was recovered in that case.
- On Sept. 19, 1994, a 25-year-old woman was walking on Twinbrook Parkway around 10:20 p.m. when the suspect approached her from behind while armed with a knife. The suspect dragged her to the side of her residence where he attempted to rape her. The victim successfully resisted the assault, fled, and called police.
- On Oct. 3, 1994, Le Bich-Thuy, 42, was found dead outside her home in the 1600 block of Martha Terrace in Rockville. Police discovered that Bich-Thuy had been assaulted, raped, and then strangled. Police believe she was last known to be alive around 10 p.m. on Sept. 28, 1994, as she left the Twinbrook Metro station. The suspect's DNA was also recovered in this case.
Creating a composite
Based on a DNA analysis, police concluded that the same suspect had committed the crimes in 1989 and the 1994 rape and murder of Bich-Thuy.
Recently, detectives gave the DNA to Parabon NanoLabs, a DNA technology company in Virginia, which uses DNA phenotyping to predict the physical appearance and ancestry of a person.
Parabon–using predictions about the suspect’s ancestry, eye color, hair color, skin color, freckling, and face shape–created the composite photo released by police Monday.
While a potentially useful tool, police cautioned that the snapshot used assumptions about the suspect's age and body weight, which cannot be determined from DNA. The snapshots are also not considered an exact replica of appearance, which can be altered by factors like smoking, diet, drinking, facial hair and hairstyle.
Nevertheless, detectives released the composite with the hope that someone will recognize the suspect and provide information to investigators.
Police asked anyone with information about the suspect or the investigation to contact the Major Crimes Division at 240-773-5070. Anonymous tips may be made to Crime Solvers of Montgomery County, which is offering a reward of up to $10,000 for information that leads to the arrest of the suspect. Crime Solvers of Montgomery County can be reached at 1-866-411-8477 (TIPS).