TERRE HAUTE, Ind. (AP) — The U.S. government has put to death an Iowa chemistry student-turned-meth kingpin convicted of killing two children and three adults. It is the third execution by the federal government in one week after a hiatus of nearly 20 years. Dustin Honken, who prosecutors said killed key witnesses to stop them from testifying in his drugs case, received a lethal injection at the Federal Correctional Complex in Terre Haute, Indiana. Two others were also put to death this week: Kansan Wesley Purkey and Oklahoman Daniel Lewis Lee.