Jeff Dellinger is a former NSA agent, who worked for them as an independent contractor.
Alongside co-worker Tyler Hopkins, he started to listen on Alicia Florrick’s phone calls and messages after she represented an Arab-American translator Danny Marwart, who worked for the military until he was accused of collaborating with the Taliban. When Jeff and Tyler heard that Alicia is representing Chumhum in a lawsuit against NSA, and the warrant for listening Alicia’s conversations was almost expired, they purposely found another reason masked as possible terrorist connection to extend eavesdropping – a call from Zach Florrick’s Somalian ex-girlfriend, Nisa.
Later he contacted Florrick/Agos for legal advice because he took home a flash drive from work to supposedly download a drawing he made at work for his sister’s kids, but there were also some confidential data on the flash drive. Florrick/Agos’ strategy was to present him as a whistle-blower who took the flash drive because he was aware of his boss Mr. Froines’ wrongdoing, accusing therefore his boss for using surveillance facilities to eavesdrop on his ex-wife. While representing him, Alicia realized that the NSA is spying on her and her contacts, immediately warning Peter Florrick. The charges against Jeff were eventually dropped but for safety reasons he moved to Reykjavik.
On one occasion, Jeff helped Alicia in a lawsuit by testifying about a Spoiler app, originally designed for entertainment purposes such as prediction of a TV series plot, but also used by the NSA for better surveillance. Alicia managed to contact Jeff on Iceland and he recorded himself explaining how valuable and expensive Spoiler app is for the NSA.
When his mother passed away, Jeff planned to attend her funeral but got scared of the airport security at Toronto Pearson International Airport and changed his mind of passing the border in the last minute. Still, he was noticed by both USA and Canadian officers and caused fight between them. Alicia and Lucca Quinn were his lawyers on the trial that was held at the airport. During the trial, Alicia found out that Jeff leaked secret military information about Massoud Tahan, thus committing treason. That leak was the reason that got an innocent man fired – Captain Terrence Hicks, whom Alicia admired. Despite Alicia’s and Lucca’s opinion of Jeff’s guilt, they managed to secure him an asylum in Canada. However, Jeff raised interest of the Canadian version of the NSA, Communications Security Establishment (CSE). Although he has avoided prison in USA, his fate is unknown due to unknown intentions of CSE regarding Jeff’s knowledge of NSA.