The action reverses the Legislature's decision last year to repeal capital punishment.
The vote Tuesday overturns the Legislature's action from May 2015, when lawmakers abolished the death penalty and overrode a veto by Republican Gov. Pete Ricketts.
In response, Ricketts helped finance a signature-gathering campaign that put a measure on the ballot to restore the death penalty.
Nebraska hasn't executed an inmate since 1997, when it used an electric chair. It has never carried one out with its current lethal injection protocol. Ten men currently sit on death row.
Nebraska had been the first conservative state to abolish the death penalty since North Dakota in 1973. Ricketts argued that lawmakers who supported the repeal were out of touch with their constituents.
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