1) suženje raspona afekta: this is called "affect" in English - the conscious subjective aspect of an emotion considered apart from bodily changes; also: a set of observable manifestations of a subjectively experienced emotion <patients…showed perfectly normal reactions and affects

(2) ubistvo iz afekta: in this case, it's not "affect" (false friends), but "uncontrolled emotion". Ubistvo iz afekta would be "passion killing" or "killing in the heat of the moment", and the perpetrator would most likely be charged with voluntary manslaughter.