Here is another possibility we need to look at. Over seven thousand men were paroled at Wittsburg and Jacksonport combined, total aggregate. Out of all those only one man was not paroled and that was Tim Reeves. Tim was sent to the St. Louis prison. On the Price raid through Mo. in 1864 Reeves and company executed Major Wilson and some of his men.
What I am getting around to is this. If the Feds would not parole Tim, it shows they were still hot over the Wilson incident, it had been less than a year, and some people may have executed your seven men to get even.
It looks like some of the McGee/Cato gang may have been in Tim Reeves 15th Mo. Cav.
I found William Cato, David Reed, James D Dennis, W. M. Dennis and there may be more.