The 2026 NGCRC 29th International Gang Specialist

Training Conference (Aug. 3 - August 5, 2026):

A Look at the Presenters

Last Updated: Aug. 30, 2026

Sally-Ann Ashton, Ph.D.

            Dr. Sally-Ann Ashton is the Director of the Center for Crime, Urban Research, and Education, University of Houston Downtown, Houston, TX. She has an MPhil in Criminological Research (University of Cambridge, England) and an MSc in Investigative Psychology (University of Huddersfield, England). Her Ph.D. investigated the psychological and social risk factors associated with gang membership, group offending and desistance from crime. She was a recipient of a Frederick Milton Thrasher Award in 2017 for superior accomplishments in gang research and in 2020 for superior accomplishments in gang training. Her current research includes juvenile gangs, the policing of gangs and gang-affected communities, child criminal exploitation, and violent offending.

Andy Bain, Ph.D.

            Andy Bain is an assistant professor of Criminal Justice Studies at Westminster College, PA. He holds a Ph.D. in Offender Behavior, a Msc. Criminal Justice and a Graduate Diploma in Psychology. Andy has authored, and edited numerous books, chapters, and articles, on the outlaw motorcycle gangs; law enforcement and technology; and, professional risk working with mental health, social care, and criminal justice, publishing with a number of leading international academic and professional journals. His professional background includes four years with the National Probation Service (England & Wales) and six years running a successful Criminal Justice Consultancy Group, providing guidance and advice to law enforcement agencies and correctional bodies. This, in turn led to the publication of a number of local and national policing and corrections reports.

Kenneth Davis

            Kenneth Davis retired from the Yonkers Police Department in July of 2017. From 1985-1990 he was assigned to uniformed patrol (task force and public housing) and plainclothes (street-level and undercover narcotics). From 1990-2000 he worked street gangs, graffiti crimes and police academy. From 2000-2009 he was assigned to several middle/high schools as a school resource officer. In 2009 - 2017, as a detective, he continued investigating street gangs, narcotics (search warrants) and graffiti crimes. As the departments liaison, he assisted the YMCA’s Cure Violence/SNUG Program and the Westchester County Department of Corrections Re-entry Program. From 2017-present, he is a NYS private investigator and a graffiti/gang specialist presenting at various regional, national, and international conferences.

Dr. Gregg W. Etter Sr., Ed.D.

            Dr. Gregg W. Etter Sr., Ed.D. is a Professor of Criminal Justice at the University of Central Missouri. He retired as a Lieutenant with the Sedgwick County Sheriff’s Office after serving from 1977 to 2006. He is rated as a gang expert by the National Gang Crime Research Center. He has written extensively and presented classes on gangs, white supremacist groups and police management topics in the United States and Canada. Dr. Etter earned his Bachelor’s and Master’s degrees from Wichita State University and his Doctorate degree from Oklahoma State University. Dr. Etter is the author of numerous books, book chapters, edited and refereed articles. His latest book is: Gangs and Organized Crime which he authored with Dr. George W. Knox and Dr. Carter F. Smith.

            George Knox earned his Ph.D. in sociology from the University of Chicago. He has extensive field experience with gangs, including interviewing gang members, gang leaders, and gang victims. He has taught in the field of criminal justice and sociology. He serves as the Executive Director of the National Gang Crime Research Center. He was the author of the first full textbook on gangs (An Introduction to Gangs) and other books and monographs on gang topics. His research interests include how to deal with gang problems in probation/parole, juvenile corrections, adult corrections, and gang threat analysis — examining the gang as a unit of social organization.

Douglas L. Semark, Ph.D.

            Douglas L. Semark, Ph.D.is a nonprofit leader with four decades of experience, including 17 years as Executive Director of the Gang Alternatives Program (GAP) in Los Angeles. Semi-retired, he now serves as Executive to the Board and Chief Learning Officer. He provides gang and violence prevention professional development for K-12 school counselors; serves in various advisory capacities; such as the NGCRC, and works with local and national agencies in the areas of violence reduction and community rebuilding. He is currently the Director and lead instructor of the Gangfree Life Academy^®.

Dr. Martha Wall-Whitfield

            Dr. Martha Wall-Whitfield is an educator from Little Rock, Arkansas where she is currently the Founder and Principal of Legacy Christian Academy, a private Christian school for at-risk youth and kids from trauma. She was formerly the District Principal for all juvenile correctional facilities in the state of Arkansas and also served as Principal at the state’s largest juvenile facility for incarcerated youth for seven years. She has taught for over 16 years at the University level as an Assistant Professor for Averett University and as an Adjunct for Virginia Commonwealth University, University of Arkansas Little Rock, and Arkansas State University. Dr. Whitfield is a mom of five and a Mimi to five. She is active in both her church and the community as a foster and adoptive parent and foster parent trainer for the state.

Stuart Welch, J.D.

            Stuart Welch, Assistant State’s Attorney, is the Senior Contact Attorney for the Felony Drugs and Guns Unit a the Harford County State’s Attorney’s Office, where he specializes in the prosecution of drug dealers responsible for fatal overdoses. He is specially assigned to the Harford County Drug Task Force. Stuart secured the first ever second-degree murder conviction in the State of Maryland of a drug dealer who distributed drugs causing a fatal overdose. Stuart’s article “Drug Induced Homicide: Prosecuting Fatal Overdose Cases” was published in the National District Attorneys Association’s (NDAA) 75^th Year Anniversary Edition of “The Prosecutor”, the NDAA’s legal publication. He received the NGCRC’s 2025 Frederic Milton Thrasher Award for superior accomplishments in gang prosecution, the 2025 Harford County Sheriff’s Salute Award for his work in securing the first manslaughter conviction in Harford County, Maryland, of a drug dealer causing a fatal overdose, as well as the 2026 Harford County Sheriff’s Office Unit Citation for th Task Force’s superior performance in dismantling drug, firearm, and sex trafficking organizations.