"Dr. Karla Turner died of cancer on January 10, 1996, after being threatened for her work. She was just 48. Since then, several other people involved in UFO investigation have also experienced threats followed by highly unusual cancers."
Source: http://www.karlaturner.org/index.html

Karla Turner "UFO Abduction: The Secret Agenda" (1993)

Karla Turner - UFO & MIlitary Abductions - 1994 Lecture - Part 1 of 4 (High Res)

Dr. Karla Turner - The UFO Masquerade - April 8, 1995

The late Dr. Karla Turner speaking at a MUFON conference in 1995 shortly before her death: