Yesterday I watched this 2 month old podcast about Trenny Gibson and it includes some very detailed interviews with two people who have investigated her case for years. What they have found out contradicts almost everything I thought I knew about this and they say that Trenny's mom wasn't truthful about Kelvin Bowman and the night she shot him in the foot. I'd always thought the story about that didn't make sense and this podcast includes a law enforcement officer's statement about what a neighbor of the Gibson's said about seeing Kelvin on the street that night after he'd been shot, which doesn't line up with what Holly Gibson said.
The two investigators in this podcast state that Kelvin Bowman and Trenny Gibson were in a relationship and that she would leave her window open and unlocked on a particular night every week when her dad wasn't home and that Kelvin was halfway in the window when he was shot in the foot. They also say that Trenny was involved with another African American male after Kelvin and they know his identity but cannot locate him to interview him. They do not think Kelvin had anything whatsoever to do with Trenny's disappearance, nor do they think Robert Simpson did, but their interviews with Kelvin and the investigating they've done has led them to firmly believer that the Gibson family lied about a number of things, partly because they wanted to cover up their daughter's interest in African American men (either because they were racist or becuase they lived in a racist area).
They could find nothing to back up Mrs. Gibson's claim that Kelvin declared in court or anywhere else that he would kill Trenny. They also could find only Mrs. Gibson's statement that Robert went to "track a bear" and left Trenny to walk down the trail alone.
Interviews they've conducted with former classmates of Trenny's have uncovered stories of pretty extreme family dysfunction at the Gibson home. Former classmates also say there were rumors that she ran into the woods that day to escape 3-4 classmates who accosted her, took her ring from her (worth $600, which shocked me as that was a LOT in the 70s), and that she only managed to slip loose from them because Robert's coat was so big that she slithered out of it, which would explain why he later had her comb in his possession. The students had heard that she ran into the woods and got lost and presumably perished, although since several dogs tracked her to the road it's equally possible that she found her way to the road and caught a ride with the wrong kind of person. One investigator believes she purposely went missing at that point and is still alive; the other thinks she is deceased.
I found the podcast very compelling and it includes pictures and names of a number of the students who were persons of interest (all are dead). I thought you'd enjoy watching it to see what you think of it.