The electric chair has been criticized because of several instances in which the subjects were killed only after being subjected to multiple electric shocks. This led to a call for ending of the practice, as being a "cruel and unusual punishment". Trying to address such concerns, Nebraska introduced a new electrocution protocol in 2004, which called for administration of a 15-second-long application of electric current at a potential of 2,450 volts; after a 15-minute wait, an official then checks for signs of life. In April 2007, new concerns raised regarding the 2004 protocol resulted in the ushering in of the current Nebraska protocol, calling for a 20-second-long application of electric current at a potential of 2,450 volts. Prior to the 2004 protocol change, an initial eight-second application of current at 2,450 volts was administered, followed by a one-second pause, then a 22-second application at 480 volts. After a 20-second break, the cycle was repeated three more times.