Sunday, October 26, 2014

Familial DNA: An Unusual Way for Your Inspector to Find the Perp - Information for Writers


I was recently chatting with David Swykert about some of the stories he'd come across while at work as a 9-1-1 operator. He introduced me to a new concept, familial DNA.

First, David, would you please introduce yourself?

David - 
I am a retired 911 operator living in northern Kentucky. I also worked as an operations manager for a large transportation company and as part of my job investigated accidents. I worked as an emergency operator for the Department of Public Safety in northern Michigan until 2006. I have written in several different genres, mystery, romance, and even some literary, short fiction and novels. I have five published novels.

Fiona - 
How did you first learn about familial DNA in crime cases?

David - 
I first heard about Familial DNA from the officer that was our CSI for our department. It's simply a DNA search that turns up no exact match, so you ask the computer for the closest match.

Fiona -
If you need a quick brush up on DNA in crime scenes go HERE

So the DNA found at a scene that did not match any of the DNA that was in the computer bank. The officer would then task the computer to find as close a match as possible, hoping to find the general family from which the possible perpetrator belonged. Is there precedent for this?

David - Yes. Lonnie David Franklin, deemed The Grim Sleeper, because of the length of time in between murders committed by him. There was never any DNA at any of the crime scenes that identified Franklin. 

The investigators found him by running a Familial DNA search which turned up his son, who was a convicted felon. This led the investigators to Franklin. 

After Franklin's arrest, the investigators tested Franklin and his DNA was a match with that found at the crime scene. 

He was caught the summer of 2009. But this case is just going to trial perhaps this year (2014). There have been volumes of appeals and briefs filed because there was never any direct evidence that connected Franklin to the crimes, and defense lawyers contend his investigation based on someone else DNA was a violation of his Fourth Amendment rights concerning illegal search and seizures.

The argument is: the inspectors had no direct evidence that connected Franklin to the crime before they investigated him.

When you run a persons records, you have to have a law enforcement purpose that allows the search, the defense contended they didn't have one. 

The courts have ruled so far in favor of the prosecution, and the trial is moving forward. But it will get appealed to higher courts. The Fourth Amendment protects you against unusual search and seizure, but of course there can be very broad interpretations of what this means.

Fiona - 
What are the arguments against using familial DNA?

David - 
Civil Libertarians argue that using someone else's DNA to justify investigating someone else violates the Fourth Amendment that protects us against "unreasonable" search and seizure. They see this as "unreasonable." 

I really don't think an officer can "abuse" the technique. In defense, the lawyers can always ask to see who's DNA caused the detectives to investigate a defendant, discover whether that DNA close to the perpetrators, and ask about probable cause. 

Amazon Link
When I heard about familial DNA searches, I thought it would be a great hook for a crime story, which I wrote in early 2009 just before LAPD caught The Grim Sleeper using the technique.

I'm surprised crime writers haven't written a lot of books regarding the use of the technique. In mine, they catch him, but the D.A. isn't sure they can prosecute him successfully, which causes my detective, Bonnie, a lot of consternation. She knows he did it, but perhaps he can't be convicted. Which could happen out in LA. That's just getting started.
Fiona - 
Let's talk about your book. Can you give a synopsis?

David - 
This is a fictional story about Detroit Homicide Detective Bonnie Benham, who convinces the District Attorney to allow a Familial DNA search as she investigates the murder of several young girls. 

The book reveals standard investigative homicide procedures and the frustration of the officers as all leads go nowhere and the body count continues to mount. A task force is put together and Bonnie and her partner, Neil Jensen, who understands Bonnie’s frustration, become inseparable as they track this killer of children.

Fiona - 
I had never heard of familial DNA prior to your book, while it will probably be more prominent as the trials catch the imagination of writers. If a writer wants to include this twist in their plot line can you give us any more information about the process?

David - 
It's no different than a DNA search, except the lab expands the search to include DNA that is close to the DNA profile from the crime scene. The investigators then investigate the people the expanded search includes. 

Last time I checked there were only two states in the U.S. that even have a policy regarding it's use, Colorado, and California, Michigan, where my story is set, is not one of them. 

What I thought would be the hook for my story is the old: I know he did it, but I can't prove it. It took from 2009 until this year for the courts to get The Grim Sleeper into a courtroom, and this case will perhaps set precedence for the future use of the technique. I think the rest of the states are waiting to see the outcome before they write a policy.

Fiona -
What do you hope the outcome will be?

David - 
I want to see the guilty convicted. DNA profiling has worked both ways, it's freed a lot of innocent people. As unique as DNA is, I would hope the courts decide if the DNA is close enough to a match this constitutes a reasonable search. 

I'm not an expert on the scientific profiling of DNA, but I would think they can set parameters that the profile must meet, a standard, which when met, allows indicates that it is reasonable to investigate this person. 

I believe ultimately the courts will allow its use. Fingerprinting isn't absolute, and they allow it entered as evidence. So there is already precedence.

Fiona - 
David, thank you so much for chatting with us today - I can almost hear all of the cogs starting to 
whir in the minds of mystery writers.

Thank you so much for stopping by. And thank you for your support. When you buy my books, you make it possible for me to continue to bring you helpful articles and keep ThrillWriting free and accessible to all.


  1. Ha! I can see it now!
    Gruesome murder has DNA evidence. No clear match. A "close enough" match is found to Character A through a misdemeanor. Character A discovers through the investigation that her daddy isn't who she thought it was. Oops! Now her real daddy is a psycho murderer. Dang!
    That could be fun!

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