(re: Why was there never a third game?)
The Murrys also have a website at http://www.evryware.com. They were called Evryware even when Sierra was publishing their games.
I corresponded with one or two of the Murrys in the past. They said that there were arguments between Ken and and them about what direction the series would be taken. The third game was to be Manhunter: London. Low sales supposedly was not an issue, as apparently the games were critically acclaimed and sold well.
There was a page on the Evryware website about Manhunter 3 a few years back (evryware.com/manhunter3 I think, it’s gone now). I guess one day they decided they were going to make it (the year 2000 or so). They had an email addressmanhunter3@hotmail.com . I remember when I e-mailed them, they mentioned that they were planning on remaking the first two games as well.
Just now I was snooping around on the Evryware site…you can click on the tiny icon in the lower left to view statistics on the site’s visitors, referring websites, etc. That led me to this page eventually: http://www.evryware.com/products.htm, which still has a mention of “Manhunter 3: Ultimate Online Adventure”. So that gives you a hint of what they were planning.
Anyway I’m sure all plans are long since cancelled, especially with the death of one the siblings. If anybody wants to try to contact them though, they might respond.