The Tube Sock Killings An Anthology of True Crime

In the 1980s, a series of murders called "The Tube Sock Killings" began. We should probably start our examination of this brief but intense reign of terror with the first case where the sock was undoubtedly used in some form or other. There are other victims, from earlier, who may also have succumbed to the same killer. But less certainty surrounds these. It was August 1985 and forty-two-year-old Ruth Cooper and her boyfriend, the splendidly bearded Stephen Harkins, her boyfriend who was fifteen years her junior, were enjoying their summer break from the vocational school where they taught in their Tacoma, Washington, home.  During the second week of the month, they had a wedding to attend and had decided, following the reception in their home city, to travel south and spend the remainder of the weekend camping in a remote forest location.
They were due to return on the evening of Sunday 11th, but when they did not, friends and family members started to become concerned. For three days nothing was heard of the couple. But then, on Wednesday 14th August, a gruesome discovery was made. Some hikers were walking through the forest, enjoying the summer weather and quiet, when they came across two bodies. The first was still in his sleeping bag.
Stephen Harkins had been shot, once, in the head. The bullet wound was fatal. Then nearby, a much smaller body was discovered. This time it was Stephen and Ruth's dog, also shot. Of Ruth there was not a sign. What had happened?