Doc is a nationally-recognized expert on use-of-force, reality-based training, and the effects of stress on performance. He retired from FLETC, where he was Senior Researcher. 

Dr. Wollert is the founder of the Performance Improvement Institute, which provides consultative and training support in the areas of acute stress, simulation development, use of force training, and human performance. His career in the training field started while serving in the United States Air Force, and afforded him opportunities to develop his research-based theories on improving individual and organizational performance through a combination of training technologies and instructional methodologies. He retired as the Principal Investigator for FLETC’s Stress Research program, where he provided instructional and research-related support in the training disciplines of firearms, police vehicle operations, financial fraud, program accreditation and instructor certification.

He holds a certification from the Force Science Institute in the analysis of use‐of‐force incidents. , author of several stress-related research articles, and co‐author of Stress Exposure Training: An Event‐Based Approach in the book Performance Under Stress.