I recall the plot line and that's all

The plot is essentially a plea by two scientists to a courtroom. They are being prosecuted for blowing up a government project and half of Arizona. They were the builders of a time travel device and had returned to their office late one evening and found an intruder operating the machine. The intruder's note says he has gone to 1st Century Jerusalem to rescue Christ from crucifixion. The physics of the device mean stopping the intruder means that the machine goes bang... Does it seem familiar to anyone?