Wm Freeman's prison records are only likely to state that his crime was felony. You may be lucky enough to find details of the trial in newspaper. He was tried at Bedford, so it could be in Northampton Mercury/Bedfordshire Times, the NM I believe goes back that far.
If you are able to visit the National Archives, it would be worth checking if Wm appealed. If he did then you may find a great deal about him and his family.
I have researched convicts in the family and found that one appealed 14 times.
I am in the process of compiling information on all convicts sentenced at Bedford to transportation. So far I have details of where 700 were sent, including your Wm.
Judy