Hi, Jill,
The Union Workhouse, now known as Ditchburn Place, is actually in Mill Road. I looked up something from their records at the CCRO a while ago, but once all this holiday shutdown is over I could go up to Castle Hill and have a look for you...
regards, keith
p.s. Sounds like an interesting case, might have also been something about his demise in the Cambridge Chronicle of the time...