Wow, that's a long stretch ! Out of interest, was it actually first-degree murder (implying premeditation) ? I wonder how they proved that !
Down here murder is life imprisonment, with a minimum-non-parole period of ten years, or 17 years (depending on which aggravating factors were present in the circumstances), and a Judge can adjust up or down from there ( longest sentence in recent history, life imprisonment with a minimum non parole period of 33 years ). For a killing like Nora's, Henry would probably get around 13 years minimum non-parole -of course that would greatly depend on precisely which facts the jury/judge accepted and which they didn't/
We don't have degrees of murder, only murder and manslaughter (which has very low penalties relative to typical US sentences).
Under our system I would say it is most likely that Henry Allen would have been out on parole after 14 years or so.
Interesting contrast between our justice systems, comparable crimes would get very different sentences (well, they'd both be life imprisonment, but the non-parole periods here would be about half). Still, our country has a very high imprisonment rate, not that much less than the USA.
Cheers.