Got DNA? Six Tips for Defense Attorneys

TIP 1: Partner with an expert.

As an attorney, you have the critical legal skills to defend your client. Forensic DNA experts fill in the gaps. They have the expertise and specialized software to read and interpret DNA files. They are consultants and coaches who play a key role in the justice system by supporting you in the work you do.

These days, DNA typing is exquisitely sensitive and more open to interpretation than ever before. Low-level mixed DNA profiles dominate the scene. If you have a DNA case, I encourage you to get some help. Your expert will inform you about the strengths and weaknesses of the DNA evidence in your case so you can give your client the best defense possible.

TIP 2: If your client can’t pay, the courts may.

DNA experts consult for private attorneys, but they also work with public defenders. If your client is indigent and DNA is a crucial factor in the case against him/her, the courts will likely pay for an independent review. Seasoned experts are accustomed to working without a retainer in such instances. Instead, they ask the attorney to secure a judge’s order guaranteeing their fees (usually with a dollar cap) and then invoice the court later, when their work is complete.

TIP 3: Check credentials

Don’t rely exclusively on expert listing services or other directories. Some listing services are “pay to advertise” and don’t vet the competencies of their experts very carefully. Others are free to the experts but make money by adding a finder’s fee on top of the expert’s usual fee, passing that cost along to you.

Visit the websites of forensic DNA experts directly and read their CVs. (Try Googling “forensic DNA consulting, forensic DNA expert” etc.). Home in on ones who have advanced degrees and list their cases by name (e.g. “People v Jonathan Parker”) and attorney (“Marcus Rico, Public Defender, Alameda County”). Successful experts welcome close inspection because they have many well-satisfied clients who will give them strong endorsements, and they have the credentials that make juries listen.

TIP 4: Know what to expect.

Most Forensic DNA experts will begin by giving you a complete list of the DNA discovery they need from the crime lab (which you can give the DA). While your expert is waiting for the materials to arrive, she can review the crime lab reports, police reports, and any other pertinent documents you already have.

Once the full DNA discovery packet arrives, it may take your expert a few weeks to organize it, review it, and arrive at an opinion, especially if your case involves low level, complex mixed DNA profiles. If you need speedier service, your expert may be able to shift her work around to accommodate your needs, but the more time you give your expert, the better.

TIP 5: Make sure your expert has STRmix.

Probabilistic genotyping is the new “gold standard” for DNA mixture analysis, and most crime labs are using a software program called STRmix. Make sure your expert has access to, and experience with, this software, especially if the crime lab in your area uses it.

FINAL TIP: The best experts are skilled teachers.

Obviously, your forensic DNA expert needs to be a top-notch forensic scientist. But that’s only part of the story. The best expert witnesses are also master teachers. Great experts can explain their findings clearly, not only to you, but to judges and juries.

Not all competent scientists are good communicators. Before you hire your expert, talk with them on the phone (or, even better) in person. Make sure they have a knack for teaching. Ask them some challenging questions and see how they answer them. You don’t want your expert to confuse the jury or put them to sleep. If you’ve asked your expert to testify, it’s because you think their opinion will help your case. Make sure your DNA expert has experience with teaching non-experts (e.g. college students, attorneys, juries, the general public) and can get complex ideas across clearly and convincingly.

Want to learn more? Browse my website and read my CV. I’ve been a forensic DNA expert for more than 20 years and would love to hear about your DNA case and see if I can help.

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