<Li> Gabriel Waincroft ( Christopher Sean ) is the younger brother of Malia Waincroft , the late wife of Chin Ho Kelly . As an adolescent he repeatedly got into trouble with the law and Malia went to Chin , then her boyfriend , for help in setting him straight . Gabriel was initiated into a gang after killing Chin 's father and rose through the ranks of the ( fictional ) Culiacan cartel based in Sinaloa , Mexico . With Wo Fat 's death , Waincroft is now the team 's primary antagonist . He has been described as daring and ambitious , particularly after he had his men attempt to assassinate the heads of three different criminal syndicates during a high - profile boxing match ( the attempt was discreetly foiled by Five - 0 ) , in the episode `` Ka Makau kaa kaua / The Sweet Science '' . In `` Pa'a Ka ' ipuka I Ka ' Upena Nananana '' , he was badly wounded and died in surgery from cardiac arrest . His daughter Sarah is currently being cared for by Chin as her legal guardian . </Li>
<Li> Gabriel Waincroft ( Christopher Sean ) is the younger brother of Malia Waincroft , the late wife of Chin Ho Kelly . As an adolescent he repeatedly got into trouble with the law and Malia went to Chin , then her boyfriend , for help in setting him straight . Gabriel was initiated into a gang after killing Chin 's father and rose through the ranks of the ( fictional ) Culiacan cartel based in Sinaloa , Mexico . With Wo Fat 's death , Waincroft is now the team 's primary antagonist . He has been described as daring and ambitious , particularly after he had his men attempt to assassinate the heads of three different criminal syndicates during a high - profile boxing match ( the attempt was discreetly foiled by Five - 0 ) , in the episode `` Ka Makau kaa kaua / The Sweet Science '' . In `` Pa'a Ka ' ipuka I Ka ' Upena Nananana '' , he was badly wounded and died in surgery from cardiac arrest . His daughter Sarah is currently being cared for by Chin as her legal guardian . </Li>
who plays chin ho kelly 's brother in law
who plays chin ho kelly 's brother in law
Christopher Sean
Christopher Sean