🧬 This is Part 2 in a 2-part series exploring DNA as a crime-solving tool. Part 1, where Uncovered spoke to experts to debunk three major genetic genealogy myths, can be accessed here! 🧬
By: Andrea Cipriano, MAFP
From blood to hair to bodily fluids, DNA left behind at a crime scene can help law enforcement further a criminal investigation until truth is uncovered.
The Arizona Zombie Hunter. The NorCal Rapist. The Golden State Killer.
When it was least expected, these offenders struck, slipping in and out of communities undetected. Their actions left a trail of fear and devastation that would haunt their victims and their families for decades to come. Despite facing the challenge of limited information, only a few sketches, and vague descriptions, law enforcement tirelessly pursued the identities of these elusive offenders. Their dedication to apprehending these culprits, who persisted in their destructive rampages for years, was unwavering.
Thankfully, these offenders all had one thing in common — they left their DNA behind.
Uncovered spoke to law enforcement experts to learn more about how cases, even ones that have been collecting dust for years, can be solved with forensic investigative genetic genealogy.
Detective Kurt Mehl is no stranger to working a case.
He’s seen it all — investigating homicides and cold cases for over four decades. As a current course teacher for the FBI and DOJ under the International Homicide Investigators Association (IHIA), Det. Mehl tells his students that the different types of DNA found at a scene will determine the relationship to the victim and the story of the crime.
If there’s skin under a victim’s fingernails, is it their own, or does it belong to an offender? Does blood in a sink indicate something sinister, or is it evidence of a simple recent cooking mishap? Moreover, the presence of semen doesn’t always tell investigators that there was an assault.
“A great number of experts, media, and the public believe that DNA is the proof of a crime,” Det. Mehl told Uncovered. “This is completely untrue as DNA left at a crime scene is only a small part of any proof if a crime has been committed.”
That’s where good-old-fashioned detective work comes into play.
From Scene to Sample
A crime scene can contain all sorts of DNA evidence such as blood, saliva, hair, sweat, skin, teeth, semen, mucus and earwax, to name a few, so investigators need to be on high-alert for everything that could possibly be helpful in identifying who was present.
Where's the DNA?
Imagine you are a crime scene investigator called to the scene of a homicide. Evidence tells you the perpetrator likely broke into the ground floor bedroom window. Can you find the 3 pieces of DNA evidence?
The 3 pieces of evidence are revealed later in this article! Scroll to see the answer.
But, how does evidence at a scene turn into a DNA sample genealogists can use to compare identities?
Samples are collected at the crime scene with clean cotton tipped swabs and items with DNA evidence are bagged. Swabs are packaged and preserved at ambient room temperature or within a cooler. All evidence is submitted directly to a crime lab.
This is where the technical part begins.
For example, extracting DNA from blood requires immense precision and a lot of repetition.
Lab technicians fill micro tubes with the blood in question, and then add a molecular biology protein that removes contaminants from the nucleic acid. After multiple rounds of adding additional chemicals to the micro tubes to help isolate DNA, the tubes of blood are spun in a centrifuge machine multiple times.
Eventually, the DNA concentration separates from the biological matter, and it’s run through a few more tests before a computer program helps to visualize the DNA, and a profile is created.
Det. Mehl explained to Uncovered, “Law enforcement will then use this DNA source identification as part of their overall criminal investigation to determine if the DNA source was responsible for the criminal act, a witness to this criminal act or an otherwise innocent person.”
This is when the police turn to genetic genealogy databases, like GEDmatch, to connect a DNA profile to an actual individual.
How do the police use GEDmatch PRO?
As explained in Part 1 of this article series, GEDmatch PRO is a portal designated to be used by law enforcement. Police or genealogists affiliated with an agency can compare DNA profiles of GEDmatch users who have opted-in, to DNA profiles of suspects in violent crimes or unidentified human remains. Users of GEDmatch PRO and GEDmatch access the same database, but GEDmatch PRO users have to meet specific criteria in the kind of investigation they are using the database for.
Since 2018, over 400 cases have been solved thanks to people who have uploaded their DNA data to GEDmatch and chosen to be a genetic witness and help name the nameless.
Let’s look at some high-profile cases that were solved because of DNA evidence.
The Arizona Zombie Hunter
On November 9, 1992, detectives in Phoenix, Arizona, made a heartbreaking discovery.
Twenty-two year old Angela Brosso was found dismembered and assaulted near the Arizona Canal. She had gone out for an evening bicycle ride the night before while her boyfriend was at home baking a cake for her birthday.
She would’ve turned 23 the day she was discovered.
Her 21-speed Diamondback mountain bike was never found, keeping detectives up at night wondering what happened.
Then, in September of 1993, 10 months later, bike riders stopped along the Arizona Canal when they noticed what looked like drag marks of blood making a trail down to the water. At the end of the trail, the police discovered the body of Melanie Bernas, 17, — stabbed in the back with most of her clothing removed. She was also assaulted.
A cross, and the letters “WSC”, were carved into her chest.
Melanie was out for a bike ride when she was attacked, just like Angela. Beyond that, there weren’t many clues — but what they did have was DNA evidence from the perpetrator. Unfortunately, tests proved it did not match anyone who had been entered into the Combined DNA Index System Database (CODIS).
The case went cold for over two decades.
By 2014, DNA technology had vastly improved, and genetic genealogist Colleen Fitzpatrick, Ph.D., knew there must have been a way to identify the killer. Determined to solve the case, she employed the same methods genealogists have been using to reunite adoptee’s with their biological families; but instead of finding parents or a sibling, Fitzpatrick was looking for a killer.
Fitzpatrick approached the Phoenix Police Department with her novel methodology. After a few weeks, the genealogy method worked, and they had a hit on the family name “Miller.”
This fired up the detectives because the original investigators zeroed in on a “Miller” as a person of interest right after the murders. They obtained the person’s DNA, and had a perfect match.
On January 13, 2015, police arrested Bryan Patrick Miller and charged him with murdering the two young girls. He was 20-years old when he committed the murders. To the nation’s horror, Miller was a local celebrity who called himself the Arizona Zombie Hunter.
Earlier this year, on April 11, 2023, after a six-month bench trial, Miller was found guilty. He faces capital punishment and is awaiting sentencing.
“It’s amazing to me that after so many years, exactly one word cracked that case. And that word was ‘Miller,” Fitzpatrick told the CBS affiliate. “That was the first case solved ever using forensic genetic genealogy.”
The NorCal Rapist
Between 1991 and 2009, California investigators knew when they were entering a scene perpetrated by the NorCal Rapist. His pattern of heinous behavior was predictable.
This California offender would stalk and target Asian American women living alone in their 20’s, entering their homes, usually late at night while they slept. He would blind his victims, assault them, and then ransack their homes.
On occasion, this rapist would abduct a woman, take her to an ATM, and force her to withdraw money for him.
Desperate to catch the assailant, investigators painstakingly collected DNA evidence from the survivors and the scenes, hoping one day they’d get a match on the offender.
In 2006, the police learned that six survivors were linked to the same suspect, but without a DNA match, they would’ve never uncovered his identity.
Then, using GEDmatch in 2018 (before GEDmatch PRO), the police finally got a match to a relative of the offender. To get this match, investigators uploaded a male DNA profile from a 1997 Butte County case, where the female survivor stabbed the NorCal rapist in the arm.
“The man that tried to clean up the crime scene was unsuccessful,” Butte County District Attorney Michael Ramsey said, quoted by KCRA. “There was too much blood — he couldn’t cover his sins, his crime.”
After the GEDmatch genetic relative match, it took investigators 10 days to identify the rapist as Roy Charles Waller, 58.
A Sacramento jury convicted him on 46 counts of attacks on nine women, and he was sentenced to 897 years in prison.
Thanks to forensic investigative genetic genealogy and DNA closing this case, northern Californian residents could finally sleep soundly at night, knowing the NorCal Rapist was behind bars.
The Golden State Killer
The Golden State Killer — also known as the Vasilia Ransacker, the East Area Rapist and the Original Night Stalker (EARONS) — was a serial killer, rapist, and burglar who terrorized California from 1974 to 1986. He committed at least 13 murders, 50 rapes, and over 100 burglaries throughout the state.
Now, the killer’s mask has come off, and he has a real name. Joseph James DeAngelo.
The offender’s modus operandi involved breaking into homes at night, tying up, and raping female victims. When there were male partners present, he would stack dishes on the man’s back, threatening to kill everyone in the house if he heard them rattle.
Eventually, this violent rapist would become a cold-blooded killer, taking the lives of everyone in the homes he entered. This offender was known to steal small items from the homes of his victims as mementos, keeping them with him for decades to come.
Despite extensive efforts by law enforcement, the killer’s identity remained a mystery.
However, in 2017, Detective Paul Holes and FBI lawyer Steve Kramer uploaded the killer’s DNA profile from a rape kit to GEDmatch. From there, they were able to identify people who had the same great-great-great-grandparents as the killer in question. Working with Genealogist Barbara Rae-Venter, DeAngelo was identified, and a sample of his DNA was collected from his curbside garbage can.
DeAngelo was arrested in April 2018 and charged with eight counts of murder, with additional charges added later.
In March 2020, DeAngelo’s attorneys attempted to have his guilty pleas thrown out, claiming that they were made under duress. However, a judge denied the motion, and in August 2020, DeAngelo was formally sentenced to life in prison without the possibility of parole.
The Golden State Killer’s reign of terror has finally come to an end thanks to investigative genetic genealogy and DNA comparison. Justice has been served for his numerous victims and their families.
The Future of Solving Crimes with DNA
“I have witnessed in my 41 plus law enforcement career an amazing improvement in all facets of technology over this time,” Det. Mehl explained to Uncovered.
His own expertise within law enforcement seeing the development of DNA technology tells him the future for genetic genealogy and crime solving is bright.
“In my Cold Case Unit, we regularly submit evidential items that have been previously tested for DNA as the technology has advanced greatly and quickly,” he shared, adding that DNA can be detected in smaller and smaller amounts, making it easier to identify perpetrators with just a sliver of evidence.
As for the future usage of genetic genealogy in a law enforcement context, Det. Mehl feels that their symbiotic relationship is here to stay.
“Crime scene searches have radically changed and crime scene investigators have become more trained in identifying potential items that may contain DNA at crime scenes,” he concluded.
Genetic genealogy has proven to be a powerful tool in solving cold cases and providing answers to families of victims. With the help of technology and the willingness of individuals to upload their DNA profiles to public databases like GEDmatch, law enforcement can continue to uncover important leads, and bring justice to those who have been wronged.
By taking this small step, you could potentially help solve a crime, and make a significant impact in someone’s life.
Where's the DNA? — Answer!
- A sweaty fingerprint! Sweat can contain DNA so it’s possible to retrieve it from latent fingermarks, although the success of the technique very much depends on the quantity and quality of the DNA.
- A hair strand on the window handle.
- Blood droplet, most likely from someone getting cut while unlocking the inside window lock.
Thank you to everyone who answered our survey from Part 1 of this series. Below are the results, and answers to the questions you asked experts!
Survey Question Responses
How would this be used if you’ve never done anything wrong?
“This is my favorite question,” Det. Mehl writes. “Law enforcement can only use your DNA to get you into trouble if you got into trouble and left your DNA at the scene of the trouble you got into!”
In other words, if you’ve never done anything wrong and opted-in to have your DNA compared with known DNA profiles from crime scenes, your profile would only be used to include or exclude your genetic line to an individual.
Det. Mehl continues: “If you have a family member who has a criminal history and you submit your DNA to the genealogy databases, your DNA information is available to research for past and future criminal investigations where DNA was recovered and developed for genetic genealogy searching.”
Kurt Mehl has had a law enforcement career that’s spanned over 40 years. His time with a badge has taken him from being a police detective investigating narcotics and financial crimes, to training future officers in New Jersey, to investigating cold case homicides in Florida. Det. Mehl also teaches a week-long course to investigators discussing no body homicide cases that was developed along with the FBI Behavioral Analysis Unit.
Colleen Fitzpatrick, Ph.D., the President and Founder of Identifinders International LLC, is widely recognized as the founder of modern Forensic Genealogy. She has worked on several hundred cold case violent crimes and Doe cases using genetic genealogy analysis. Fitzpatrick is also a member of Vidocq Society, a volunteer group of experts and investigators who serve as confidential consultants to assist law enforcement in solving difficult cold cases.