Synonym for laughing darkly?

I need a synonym for laughing darkly or a dark chuckle...the background of the scene I'm writing is basically that when the husband comes home and thinks the wife is cheating on him (she's not really, but just talking to a close brotherly friend), but the husband thinks they are having an affair and when she denies it and tries to explain, he laughs darkly. Is there some type of word to describe the laugh I'm getting across? Thanks!