The present study examined the effectiveness of retrieval support for witnesses who differ in working memory capacity (WMC) and source monitoring abilities. We hypothesised that the provision of retrieval support, relative to free recall, would compensate deficits linked to lower working memory and source monitoring abilities by providing more structure and context cues for retrieval. Thus, we expected no associations between recall performance and WMC and source monitoring abilities in the retrieval support group, but significant positive associations in the free recall group. This study combined data from two experiments (N = 125) in which participants either received retrieval support with the Self-Administered Interview or completed a free recall along with working and source memory tests. Contrary to our expectations, presence of retrieval support did not moderate the relationship between WMC and recall performance. In one of two source memory tests, higher source memory scores were associated with more accurate accounts in the retrieval support group, whereas in the free recall group, lower source memory scores were associated with higher recall accuracy. This suggests that individuals with lower source memory abilities may not benefit from retrieval support. We encourage replication with a more heterogeneous sample.