Diego Clare was a former JAG officer who was tasked with prosecuting Jack Curtin, a Petty Officer/SEAL accused of killing his wife, Margaret Curtin and an Unnamed Cable Repairman (UnSEALeD). At some point, Diego left JAG and began working pro bono cases. His involvement in the Curtin case prompted Leroy Jethro Gibbs to bring him into NCIS Headquarters where Diego was reunited with his old friend, Faith Coleman with the two working together with Gibbs and Agents Anthony DiNozzo and Caitlin Todd to learn everything about Curtin and the murder case against him.