Meet the Crime Scientist

How Craig O’Connor uncovers clues that help catch criminals

November 2023

by Alex Lim-Chua Wee

ocme.nyc.gov

Craig O’Connor

A half-eaten pizza crust. An empty soda can. A plate of chicken bones. To you, they’re just someone’s dinner leftovers. To Craig O’Connor, they could hold the secrets to solving a crime.

Craig is a forensic scientist. He works at one of the largest public crime labs in the country. Every year, Craig and his team receive nearly 10,000 cases. Their job is to examine evidence, or items taken from a crime scene. We asked Craig about his important work.

Did you always want to be a forensic scientist?

As a kid, I liked science and solving puzzles. But it was watching crime shows on TV that got me interested in forensic science. After college, I got my Ph.D. in genetics. (That’s the study of how traits are passed down through families.) Then I moved to New York City to work in a crime lab.

What are you looking for when examining evidence?

Often forensic scientists look for fingerprints. For example, if a car was stolen, they’ll check the steering wheel. But our lab is mostly looking for DNA. That’s a chemical structure found in your body. Everyone’s DNA is unique to them. If we find DNA, it can tell us who an item belonged to.

How do you find DNA?

Let’s say we’re studying a pizza crust. We look at the bite marks first. We use a cotton swab to collect a saliva sample in a test tube. Then we add chemicals to the tube to identify any DNA.

Build Knowledge

What is DNA?

Every cell in your body contains a chemical structure called DNA. It’s passed down from your parents. DNA contains shorter sections called genes. Each gene is like a sentence in your body’s instruction manual. Your genes determine your eye color, hair color, and more.

What’s the most challenging part of your job?

Many cases can be upsetting. It’s easy to feel sad or angry that these crimes happened. It’s important that as scientists, we stay focused. Our job is to help find the answers and bring justice to people who have been hurt.

Is your job really like it looks on TV shows?

When you watch forensic scientists on TV, they’re usually working on one case at a time. In real life, we often work on thousands. It can also take us 30 to 60 days to get results from testing. On TV, you see it all get solved the next day!