Some careers look linear from the outside. From the inside, they’re a sequence of puzzles — each one harder than the last, most of them decades old, and all of them connected to people whose names you’ll probably never know.
Cristina Servidio, Chief Operating Officer and Technical Leader at DNA Labs International, describes her job this way: reviewing cases with clients, troubleshooting what technology might finally get a result, supervising analysts, tracking case flow, writing SOPs. Multiple hats. No two days the same.
But the part she comes back to is the cold cases.
“There’s nothing more rewarding than working on a case like 50 years old, 40 years old, and trying to figure out what is going to get a result.”
That puzzle instinct — the desire to keep trying strategies until one works — is what DNA work, at its best, actually asks of the people doing it. The easy cases matter. They need to be solved too. But the cold ones are where analysts find out what they’re actually capable of.
What the Work Is For
One of the structural realities of forensic DNA analysis is deliberate distance from outcome. Labs receive enough case information to do the work — the alleged circumstances, what needs to be tested — and leave the rest out. The reasoning is sound: bias is a real threat to defensible science. But it also means analysts rarely hear what their results meant to the people involved.
Servidio described what happens when that distance collapses, even briefly. A survivor named Julie Weil came to DNA Labs International and spoke directly to the analysts and serologists about her experience. Later, at ISHI 35, Servidio presented a case involving three teenagers whose throats had been cut and who had been sexually assaulted — and who survived. Fifty years later, the case was solved. The survivors went public. They talked about the impact it still had on their lives. They said they were able to forgive their attacker.
“Seeing that impact really just drives it home. This is why we’re here.”
It’s not a detail most labs build into their workflow. But it’s the kind of thing that makes the ten-hour days make sense.
Where SNP Technology Is Going
DNA Labs International has its own genealogist team — separate from the analysts who do the SNP work. Servidio noted that genealogists often specialize by region, a detail she said surprised her when they first started bringing genealogists on staff.
On the SNP side, her focus is on what the technology can now do with the quantities labs actually have. Early SNP testing required substantially more DNA than forensic samples typically yield. That bar has come down significantly. Labs that have profiles sitting in CODIS without a hit now have another option — a path to extract something more from the DNA they already processed.
The next frontier she’s watching: twin differentiation. Standard STR testing produces identical profiles for identical twins. Whole genome sequencing can potentially find SNP-level differences between them. It’s a narrow application, she acknowledges — but for the cases where a suspect says it wasn’t them, it was their twin, it matters considerably.
Advice for Students
Servidio completed a bachelor’s and master’s in biomedical engineering at Catholic University of America, followed by a master’s in forensic molecular biology from George Washington University. Her path into forensics included an internship at the Armed Forces DNA Identification Laboratory in Rockville, Maryland — an experience she credits with confirming that the work was what she actually wanted.
Her advice is consistent: get an internship. Not to build a resume, but to verify. Some people start down the forensic path and realize they’d rather be on the CSI side, or somewhere else entirely. Better to find that out early, while you can still redirect.
DNA Labs International takes interns. For students willing to make their way to Florida, there are opportunities to shadow lab analysts or assist with validation projects.
On the Work
At one point in the conversation, Servidio described the moment a cold case strategy finally works: “You go home and you feel the sense of like, oh my God, we got it.”
She said it without drama. It’s just what happens when you’ve tried everything, and then something works, and you know — because you’ve seen it — what that result might mean to someone you’ll never meet.
That’s the job. It’s the part that doesn’t get covered in the SOP.
Cristina Servidio presented at ISHI 36 in Palm Beach, Florida. DNA Labs International is a private forensic DNA laboratory located in Florida. Learn more about ISHI and upcoming programming at ishinews.com.