The suspect, Kenneth Earl Day, died in March 2017 in West Virginia, at 52 years old.
Investigators collected DNA during the initial investigations but no matches were found in the national DNA database.
The first case was a rape that happened on June 25, 1989 at around 10:15 p.m. The victim, who was 52 at the time, was walking on Lewis Avenue when police said Day approached her from behind, assaulted her and raped her.
The second case was a rape and homicide. On Oct. 3, 1994, Le Bich-Thuy was found dead next to her house in the 1600 block of Martha Terrace. Police said she had been assaulted, raped and strangled. The last time she had been seen alive was Sept. 28, as she left Twinbrook Metro station.
Investigators at the time determined that the DNA found in both cases belonged to one suspect but were unable to find out who without matches in the national database.
In 2017, cold case detectives sought the help of a DNA technology company in Virginia that specializes in DNA phenotyping — predicting a person’s physical appearance and ancestry from DNA. The company, Parabon NanoLabs, created a composite showing how the suspect looked based on his DNA.
Detectives then sought help from the public in identifying the man.
Parabon submitted a genetic data profile to a publicly available genealogy database, GEDmatch, in an attempt to find relatives of the suspect.
Additional investigation led to detectives identifying Day as the suspect in both cases. The DNA left in both cases matched DNA samples taken from Day’s autopsy.
Cold case detectives are investigating other crimes that Day may have committed.
Below is a list of prior addresses for Day and the dates that he lived there:
- 1989: 500 block of Beall Avenue, Rockville, Maryland, 20850
- 1988: 100 block of Willowdale Drive, Frederick, Maryland, 21702
- 1990-1991: 20000 block of Frederick Road, Germantown, Maryland, 20876
- 1990: Unit block of Whetstone Drive, Gaithersburg, Maryland, 20877
- 1992: 11700 block of Zebrawood Court, Germantown Maryland, 20876
- 1993-1994: 12300 block of Selfridge Road, Silver Spring, Maryland, 20906
- 1994: 2000 block of Baltimore Road, Rockville, Maryland, 20851
- 1997-1999: 14400 block of Belvedere Drive, Woodbridge, Virginia, 22193
- 2002-2004: 11800 block of Renner Road, Keymar, Maryland, 21757
- Late 2000s: 10300 block of Mumma Ford Road, Rocky Ridge, Maryland, 21778
- Late 2000s: Unit block of Heavner Grove Road, Buchannon, West Virginia, 26201
Anyone with information is urged to call cold case detectives with Montgomery County police at 240-773-5070.