Well, your husband is correct in this partiular issue. Yes indeed, God IS a murderer and by extension explain to your husband that so are the WT Society leaders, the GB for allowing innocent children to be murdered and sacrificed by instructing their JW followers- the parents - to NOT give blood transfusions to their minor children in need of transfusions to save their lives.
I find it interesting that your husband can on the one hand appear to be indignant over God murdering Jesus, or allowing children to be killed- yet he has no moral compass regarding his own unethical treatment of you or your children in your marital strife at the moment. Seems somewhat hypocritical of him . But that again is a JW trait in which they have been trained by the WT Society to see the bad in others and other situations, but are unable to point the finger at themselves personally. WT leaders do this all he time so it's no surprise that JW's like your husband can do it. He's been TRAINED to think this way in his mind. WT Society trains JW's to compartmentalize sin so that WT agendas can still be followed yet mind controlled J-dubs won't feel qualms of guilt about anything. They learn from the top of the organization