Jonathan Washington

At the beginning of the series, Jonathan Washington had just skipped bail for drug smuggling charges, only to be captured by Rally Vincent. Actually, Washington was working for Edward Haints' gun-running ring and operated an entire warehouse filled with illicit firearms... firearms that Rally, with a little "help" from Bill Collins, were able to prevent hitting the streets.
However, since Washington was now a vital witness to the gun ring, he was taken to an A.T.F. safehouse outside Chicago. He had tried to persuade Rally to help him escape the safehouse because he now feared for his life. He knew that George Black, the head of the A.T.F.'s Chicago office, was also a partner of Haints and had now sent a hitman after him. When Rally refused to help him escape, he was able to leave a fake Rolex watch and a scrap of paper with the address of his "daughter" on it with May. In fact, the paper held an Internet address and the watch had an access code to the shipping dates of the gun ring engraved on the back of the watchband's latch.
True to his warning, Washington did meet his end when Natasha Radinov, using a copy of Collins' cardkey and access code, entered the safehouse, and slaughtered Washington and the A.T.F agents guarding him. (From Wikipedia)