From 2014:

http://www.kctv5.com/story/25732970/...urning-vehicle

Three people whose bodies were found inside a burning pickup truck on June 9 were shot before they were burned, Surprise police said Wednesday.

Police identified the victims as 57-year-old Lisa Baker and 41-year-old William Kling, both of Wittmann, and 25-year-old Garth Tuggle of Phoenix...

The truck was found about one mile west of 219th Avenue near Sun Valley Parkway after a caller reported the fire about 2:40 p.m., according to Surprise police Sgt. Mike Donovan.
http://globegazette.com/news/local/f...8b4c296bb.html

Lisa Baker, 57, of Wittmann, Ariz., was found June 9 in the back of a burned pickup truck in a remote area of Suprise...

She was a research physiologist at the University of Arizona but most recently graduated from Le Cordon Bleu Institute with a culinary degree...

Both Tuggle and Kling have criminal records, according to Arizona court records.
Still unsolved:

http://www.abqjournal.com/792851/pol...-homicide.html