I just finished this night wounds time by Shawn Sutherland and it is a great book. There is so much information about the case you will never find else where and thankfully, the girls' cases have been reopened!
This book has many theories, and after reading it I would like to offer my own.
First off, Stacie's 1969 Ford Mustang was found parked in a strip Mall in Dallas, TX located on Forrest Lane. You know how when you're a kid in high school, there's always a major hang out spot, whether it be a park, movie theater parking lot or mall? Well, for the kids in Dallas and Carrollton in 1988, the "chill" spot was Forrest Lane, where partying, cruising, get togethers and drag racing would occur. After the girls were seen at the Steak and Ale, it was said (but not confirmed) that they were also sighted on Forrest Lane. We know they had to have been here at some point, since Stacie's Mustang was found off of Forrest Lane.
My theory is that the girls went out with no plans that night, just wanted to wing it. I think they met up with someone they both knew and trusted, who offered them a ride else where. Stacie's car was found locked and undisturbed, so I think she had every intention of returning to it, whether the next morning or in a few hours. I think from then on, it's anybody's guess but does not look good.
I also strongly suspect Stacie's then boyfriend, Mr. Lawton. My reasoning for that I will list:
1. He was abusive, jealous and possessive towards Stacie. His other lovers and wives would come forward to say he was also violent towards them.
2. He didn't care Stacie vanished. He declined to help her mother (who said she treated him like family) put up missing posters of the girls. In fact, he wasn't upset at all as a got a new girl friend a month or so later.
3. He confessed to his new girlfriend after Stacie vanished that he killed both the girls by beating them with a shovel, and buried them in an old, forgotten cemetery. He would later change his story to say he dumped them in a fish hatchery. (The cemetery was searched, but nothing ever became of this because, but I must say the search wasn't very thorough, they just searched for disturbed ground).
4. He would soon move out of TX, saying he had no friends of job opportunity there. Weird, since his dad owns chains and chains of different stores and businesses in TX. Surely his father would have given him a job.
5. He changed his name.
Now, he passed a polygraph test, but I have come across many cases where someone has no conscience, and pass it with ease, even though they are guilty. He was ruled out as a suspect just by the polygraph test despite his confession, and I think this is why this case is unsolved.
I am so happy they reopened the case, I have always thought the girls were still at least nearby Carrollton. Those girls' families are still actively searching to this day, it is so heart breaking, this is definitely one of the top cases for me I want to see resolved, within the next year. God Bless Stacie, Susan and their families.