The first sketch shows the possible suspect at 25 years of age. A second composite sketch shows the same person at 45-years-old. (Montgomery County Police Department) The first sketch shows the possible suspect at 25 years of age. A second composite sketch shows the same person at 45-years-old. (Montgomery County Police Department) 
 
 - Montgomery County police said they have used DNA evidence recovered from separate crime scenes of a rape and murder that each happened decades ago to construct composite sketches of a possible suspect. 
 
 The string of brutal attacks took place in the Rockville area beginning with the assault and rape of a 52-year-old woman on June 25, 1989. Police said the victim was approached from behind and sexually assaulted as she was walking on Lewis Avenue in Rockville. Investigators recovered the suspect's DNA from this case. 
 
 Police connected that attack with the rape and murder of 42-year-old Le Bich-Thuy in 1994. She was found strangled to death outside of her home on Martha Terrace on Oct. 3, 1994. Investigators found she was last known to be alive several days earlier leaving the Twinbrook Metro station on Sept. 28. 
 
 A couple who lived in the area back then recalled the feeling of neighborhood when the crimes happened. 
 
 “I was terrified,” said Peggy Bur. “My children were young. I had a 10-year-old and 5-year-old." 
 
 “Everybody was quite upset about it,” said Tony Bur. “Especially the fact that there was no suspect.” 
 
 After using DNA evidence recovered at both of these unsolved crimes, a DNA analysis determined that the same suspect committed both crimes, police said. 
 
 Parabon NanoLabs, a DNA technology company in Virginia that specializes in predicting physical appearance from unidentified DNA evidence, was used to construct two composite sketches of what the possible suspect may have looked like when the crimes were committed and what he may look like as he aged. 
 
 The first sketch shows the possible suspect at 25 years of age. A second composite sketch shows the same person at 45 years old. 
 
 “I’m happy to hear that because it was frustrating that there was never any resolution," said Peggy. "Even though I didn’t know the woman, I still identified with her. She was not that different from me in age and she deserved some kind of justice which never came.” 
 
 Police believe the suspect is also connected to an attempted rape of a 25-year-old woman on Sept. 19, 1994. Police said the suspect, armed with a knife, approached the victim from behind on Twinbrook Parkway and dragged her to the side of her home where he attempted to sexually assault her. However, she was able to resist and get away from the suspect before contacting police about the incident. 
 
 Anyone with information regarding the suspect or anyone who believes he/she may have details that might advance this investigation is urged to contact the Major Crimes Division at 240-773-5070. For those who wish to remain anonymous, Crime Solvers of Montgomery County is offering a reward of up to $10,000 for any information that leads to the arrest of the suspect. Tipsters can call Crime Solvers of Montgomery County toll-free at 1-866-411-TIPS (8477). ||||| Police have released a composite sketch of a suspect wanted in connection with a series of rapes and a murder more than 20 years ago in Rockville, Maryland. Police were able to use the suspect's DNA to build the composite sketch. 
 
 WASHINGTON — Detectives with the Montgomery County Police Department’s Cold Case Squad released a composite sketch of a suspect wanted in a series of the rapes and a murder that happened more than 20 years. 
 
 Police said in a news release they were able to build the sketch from DNA the suspect left at the crime scenes. 
 
 The process is called DNA phenotyping, which predicts the physical appearance and ancestry from unidentified DNA. Parabon NanoLabs, a DNA technology company in Virginia that specializes in DNA phenotyping, produced the sketches that is referred to as a Snapshot composite. 
 
 The Snapshot used to the suspect’s DNA to produce trait predictions for the suspect’s ancestry, eye color, hair color, skin color, freckling and face shape. By combining these traits, the Snapshot composites were produced to show what the suspect might look like at a certain age and with a certain body mass index. 
 
 Detectives used default ages and default BMIs because age and BMI cannot be determined from DNA. 
 
 Police believe the suspect was involved the assault of three women, two of whom were raped and one was murdered. 
 
 The first incident happened on June 25, 1989, in Rockville, Maryland. Police said the victim, a 52-year-old woman, was walking on Lewis Avenue when the suspect approached her from behind, assaulted and then raped her. Police were able to recover DNA from the suspect in this case. 
 
 The second incident occurred five years later on Sept. 19, 1994. 
 
 Police said a 25-year-old victim was walking on Twinbrook Parkway when the suspect approached her from behind while armed with a knife. The suspect grabbed the victim and dragged her to the side of her residence where he attempted to rape her. The victim was able to resist the assault and flee to call police. No DNA evidence was collected in this incident. 
 
 The third incident happened on Oct. 3, 1994, when police found the body of 42-year-old Le Bich-Thuy to the side of her home in the 1600 block of Martha Terrace in Rockville. 
 
 Police said their investigation revealed that Le Bich-Thuy had been assaulted, raped and then strangled. DNA was recovered from this incident as well. Police were also able to determine the victim was last known to be alive at 10 p.m. when she left the Twinbrook Metro station in Rockville. 
 
 A DNA analysis determined that the suspect in the 1989 assault and rape had committed the 1994 rape and murder of Le Bich-Thuy. 
 
 Police are releasing the sketch with the hope that someone might recognize the suspect and be able to provide some information to police, but police caution this Snapshot might not necessarily be exactly how the suspect looks. 
 
 “It is important to note that Snapshot composites are scientific approximations of appearance based on DNA and are not likely to be exact replicas of appearance,” Montgomery County police said in a news release. 
 
 “Environmental factors such as smoking, drinking, diet, and other non-enviornmental factors — e.g., facial hair, hairstyle, scars, etc. — cannot be predicted by DNA analysis.” 
 
 Anyone who has information regarding the suspect or anyone who has details that might help investigators is asked to call the Major Crimes Division at 240-773-5070. 
 
 Like WTOP on Facebook and follow @WTOP on Twitter to engage in conversation about this article and others. 
 
 © 2018 WTOP. All Rights Reserved. This website is not intended for users located within the European Economic Area. ||||| Police released images of how an attacker connected to several crimes, including at least a rape and a murder that happened more than 20 years ago in Montgomery County, Md., might have looked at 25 years old, left, and at 45 years old. (Courtesy of Montgomery County Police) 
 
 On a fall night 24 years ago, research biologist Le Bich-Thuy boarded a Metro train in the District, exited at the Twinbrook station in Rockville, and walked home. 
 
 Bich-Thuy never made it. Someone followed her and dragged her into a side yard. She was raped, battered with a piece of concrete and strangled. The case remains unsolved. 
 
 Now, though, Montgomery County investigators say they have a rough idea of what the attacker may have looked like, because of an emerging forensic technique called “DNA phenotyping” that projects genetic clues left at crime scenes into facial images. On Monday, they released images of how the man might have appeared at 25 and 45. 
 
 “We’re looking for any new information, anything these images might prompt someone to remember,” said Sgt. Chris Homrock, head of Montgomery’s cold-case squad. 
 
 Unlike past cases in Montgomery County, when detectives employed the imaging technique, this time they were able to use identical DNA collected from two crime scenes. The other case dates to 1989, five years before the scientist was killed, and involved a woman raped after she, too, exited the Twinbrook station and headed home. 
 
 DNA at the scene in 1994 matched DNA from the 1989 crime scene, and Homrock is convinced the same man committed both crimes. Homrock also strongly suspects the man attacked other women. “I don’t think he did this just two or three times. This guy was targeting women in that area for at least five years,” Homrock said. 
 
 The sergeant and his detectives have examined two other crimes reported near the Twinbrook Metro station from that time — including an attempted rape, in 1994, by an attacker armed with a knife whom the victim fought off. The common denominator, Homrock said, was a victim who had just left the station and was probably followed — either as she walked home or took a short bus ride. Then the man would spring out just before the victim got into her residence. 
 
 “The common theme of these cases is they all start at the Twinbrook Metro,” he said. “Everything generates from there.” 
 
 [Woman found slain was biologist] 
 
 Bich-Thuy lived by herself in a house on Martha Terrace. The molecular biologist had relocated from France and had been working at Children’s National Medical Center. One of her projects involved pediatric pulmonary medicine. The well-liked 42-year-old also played cello in a community orchestra. 
 
 “She just was a wonderful person. When she smiled, the room lit up,” Ervin Klinkon, director of the Montgomery College Symphony Orchestra, told The Washington Post in 1994. 
 
 The DNA phenotyping images, generated by Virginia-based Parabon NanoLabs, rely heavily on genetic histories linked to the DNA found at crime scenes. In this case, that has led detectives to know, fairly confidently, that the assailant is white, has blue eyes and no freckles, and has a distinctive shape to his head, Homrock said. 
 
 But the technique has limits. One big one: There is no way, based on the genetic markers to know the age of the attacker, Homrock said. That is why two images were made with a 20-year age spread. Nor can the technique account for hairstyle, scars and how much a person’s appearance may have aged from smoking, drinking and diet. 
 
 Montgomery police officials term the images “scientific approximations” of appearances, rather than replicas that may help lead to the attacker. 
 
 The three crimes investigators think were committed by the same man: 
 
 On June 25, 1989, about 10:15 p.m., a 52-year-old woman was walking on Lewis Avenue when a man approached from behind, dragged her into a yard and raped her. Investigators collected evidence at the scene, stored it and years later — through scientific advances — used it as a source of suspect DNA. 
 
 On Sept. 19, 1994, about 10:20 p.m., a 25-year-old woman was walking on Twinbrook Parkway when a man approached from behind, armed with a knife. He dragged her to the side of her residence and tried to rape her. She resisted, fled and contacted police. Investigators have never been able to draw DNA from evidence at this crime scene. 
 
 On Oct. 3, 1994, the body of Bich-Thuy was found on the side of her home, and it was later determined she had been attacked several days earlier. Police had been called to her home after worried friends and co-workers hadn’t seen her. ||||| Police Use DNA to Predict Appearance of Suspect in 1989, 1994 Rapes, Murder 
 
 Detectives Seeking Public Assistance in Cold Cases 
 
 Police released these DNA-based composite sketches of a man suspected of rape and murder in 1989 and 1994. The sketches are predictors of the man's appearance at age 25 (left) and 45. Via Montgomery County Police 
 
 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).
– Police in Maryland hope to track down a rapist and murderer who struck decades ago with an image crafted using his own DNA. After 42-year-old Le Bich-Thuy was raped and strangled after leaving Rockville's Twinbrook Metro station in 1994, DNA recovered from the scene was found to match DNA in the 1989 rape of a 52-year-old woman who'd departed the same station, reports the Washington Post. But "I don't think he did this just two or three times. This guy was targeting women in that area for at least five years," says Sgt. Chris Homrock, pointing to one case in which a woman escaped an attempted rapist days before Bich-Thuy's murder. To finally catch the attacker, police turned to Parabon NanoLabs, a Virginia-based company specializing in DNA phenotyping, reports Bethesda Magazine. Two computer-generated images were created using predictions of the suspect's ancestry, eye color, hair color, skin color, freckling, and face shape. Released Monday, they show how the suspect—white, with blue eyes and no freckles—might have appeared at ages 25 and 45. In a statement, per WTOP, Montgomery County police stress the composites "are scientific approximations of appearance based on DNA and are not likely to be exact replicas of appearance." Still, anyone who recognizes the man is asked to call the Major Crimes Division. "We're looking for any new information, anything these images might prompt someone to remember," says Homrock, noting "the common theme of these cases is they all start at the Twinbrook Metro." A reward of up to $10,000 is offered for information leading to an arrest, reports Fox 5. (In another cold case, police are using Twitter in a novel way.)