1. Chief Criminalist, Tarrant County Medical Examiner's Criminalistics Laboratory, 200 Feliks Gwozdz Place Fort Worth, TX 76104-4919 and Institute of Forensic Medicine, Texas College of Osteopathic Medicine, Fort Worth, TX, US.
2. Forensic Chemist, Retired, Tarrant County Medical Examiner's Criminalistics Laboratory, Forth Worth, TX, US.
3. Examiner, F.B.I. Laboratory, 10th and Pennsylvania Avenues, N.W., Washington, D.C., US.