The co-occurrence of conduct problems (CPs) and high callous–unemotional (CU) traits specifies risk for adult psychopathy and is under a high genetic influence. A previous genome-wide pooled DNA study of 7-year olds identified a set of candidate single-nucleotide polymorphisms (SNPs) that might differentiate high CP+CU children from healthy children. We attempted to replicate an identified subset of these SNP–psychopathy associations. In a case–control design, 210 clinically referred children were partitioned into Comparison, High CP+Low CU, and High CP+CU groups and genotyped. One SNP, rs13064369, differentiated the groups but was associated with high CP, regardless of the level of CU traits, that is, the rare and heterozygote variants CC and CT were significantly more frequent in both CP groups compared with Comparisons but did not differ from each other. We replicated the finding that a polymorphism associated with the ROBO2 gene, which is involved in neurodevelopment, confers risk for the common emotionally reactive, impulsive aspects of conduct disorder, independent of concurrent risk for psychopathy.