Karns began professional life as an epidemiologist working on issues of occupational exposures. Over the years she realized that her work was nearly all litigation driven and decided to go to law school to understand why lawyers were so resistant to applying statistical arguments in their cases. She was surprised to find that while lawyers could calculate 33 1/3% quickly they stumbled on regression equations. Since then she has worked on cases of environmental and occupational exposures, pharmaceutical liability, employment discrimination, and sexual assault. Her specialty is depositions on statistical evidence.  

Karns arrived at Cornell in 2004 with her husband Tad Brennan (Cornell faculty in philosophy and classics). ILR turned out to be the perfect fit for her quirky set of skills and interests. She teaches Statistical Practice in Law and Policy, Occupational Epidemiology, and Introduction to Statistics (usually in the Spring).   

Karns holds a BA in Economics from Reed College, an Masters In Public Health from Rutgers University, and a JD from Quinnipiac University School of Law.