Johnathan Samuels was an extremest against the United States and former partner of Rick Jackson during Day 3. He was trying to release the Cordilla Virus he bought from Mitchell Stewart on American soil. When a brother of a infected and dead FBI agent came to get his brother's things, he shot Samuels in the chest because he knew he was responsible for his brother's death. Samuels died from wounds before he could tell FBI who the carrier of the final vial was.
Samuels appeared about half way through Day 3. He told Mitchell Stewart he wanted Stewart to plant a vial of the virus in the Comfort Inn and Suites Hotel or he would decrease his pay. Stewart agreed, and Samuels later infected Stewart once he was in the hotel using a remote detonator. Samuels then told President Joseph Wald that he had a list of demands he wanted him to follow. Wald said no to every demand, and the FBI managed to find Samuels' location. Samuels then called FBI Director Chris Andrews to inform him that he had his son, Jake Andrews, hostage. Samuels then blackmailed Chris to move the teams and to let Samuels escape. Samuels then continued to blackmail Chris, and finally the FBI found out about it. When Samuels created an exchange; Jake for an incriminating harddrive, FBI was secretly in on it and managed to save Jake and capture Samuels. After Rick Jackson nearly infected Samuels with the virus, he decided to help the FBI find the 12 remaining vials around the country. All but 1 was found. The one that wasn't found was in San Francisco, so Samuels was going through pictures of what the man looked like, when the brother of an infected agent shot Samuels in cold blood. Samuels wasn't able to identify the carrier before he died, but Rick Jackson and his temporary partner Charlie Edmunds were able to find him and get the final vial.