Vermont college student Michelle Gardner-Quinn’s murderer was convicted on “two-tenths of a nanogram of a suspect source DNA,” according to defense attorney David Sleigh (see CNN TruTV’s InSession reprise of the 2008 trial)—as if 2/10ths of a nanogram was insufficient for the prosecution to meet its burden of proof.

I can’t help but wonder how the jury felt about this information during the defense opening statement. Does this sound like an insignificant amount to most jurors? Do most jurors understand what a nanogram is or what DNA weighs?

According to the Molecular Research Center, Inc.:

• “Typically, the minimal amount of DNA required for 35 cycles of PCR is 0.1 - 1 ng. However, the DNAzol Direct procedure was used successfully to amplify as little as 7 pg DNA.”

PCR, as you know, is a method of DNA typing that amplifies a small sample of biological material to enable proper analysis. PCR is an accepted tool of science. It isn’t junk science.

What is PCR? I’m not only not a lawyer, but I’m also not a scientist. My writer’s brain thinks of PCR as being a little like reading a text message, filling in a lot of blanks. DNA is like strings of paired characters (scientists actually label them A, G, T, and C). A “suspect” sample of DNA contains damaged strings in which some of the pairs and characters are missing. However, by replicating the existing data and then reassembling the strings it’s possible to reconstruct the meaning or missing data. Like “TXT” or “2NTE.”

According to Yahoo Answers, a typical human cell (containing a person’s complete DNA) weighs roughly about 0.0003 g. A gram contains one billion nanograms. So, PCR can take an incredibly tiny amount of DNA and potentially compare it successfully to any murder suspect. The “2/10ths of a nanogram” of Rooney’s DNA was actually twice as much as is generally required for testing.

In other words, the amount of DNA discovered on a murder victim’s body is irrelevant. What’s relevant is how much of the DNA is “complete” and how much can be reconstructed by PCR. In this trial, the DNA was conclusively tied to the defendant.

Obviously, by the end of the trial the jury did understand that this was sufficient to prove “beyond a reasonable doubt” that the defendant was guilty.

I’ve written before about the way DNA evidence is presented to juries. I feel the judicial system needs to provide more guidance to jurors when it comes to highly technical evidence, such as DNA analysis. In the Rooney trial, I feel (for the first time since the 1995 O.J. Simpson trial) that the defense was being highly deceptive about DNA. It’s usually the prosecution.

Regardless of which side in a trial abuses DNA evidence to deceive a jury, I think this stunt should be prohibited. Judges should make very sure that expert witnesses are truthful, clear, and current in the information they provide.

I’m not a lawyer, so I have no real idea how a judge might go about this.

Maybe jurors need to be “science and math qualified” as well as “death qualified.”