From the Guardian UK:
A French serial killer dubbed the Ogre of Ardennes, who was driven by his obsession with virginity, was sentenced today to life in prison for the rape and murder of seven girls and young women.
Michel Fourniret's wife, Monique Olivier, who helped him select and lure his victims and conspired in some of the killings, was also given a life sentence. [...]
The couple met in the 1980s while he was serving a prison sentence for sexual assault, after she replied to his advert for a pen-pal.
Their letters showed they formed a pact under which, in exchange for Fourniret murdering Olivier's first husband, she would find him virgins to satisfy his obsession. Fourniret never killed the husband, but she kept her part of the bargain.
There are some horrific cases where the wives of murderers are considered suspects or guilty simply because of the marriage or because of the wife's denial of danger signs and I oppose that guilt by association. However, the evidence in this case proves that murder was one of the foundation stones of their marriage.
I consider this woman to be as guilty of these crimes as her husband is -- even those she didn't physically commit. The prosecutors proved that she was a full and freely consenting partner to his crimes and the law should treat her as such.