LINCOLN, Neb. (AP) — The mother of a woman who was murdered in a 2002 Norfolk bank robbery is gathering signatures for Nebraska’s death penalty referendum campaign.

Vivian Tuttle will collect signatures at the Scotts Bluff County courthouse in Gering on Thursday. Tuttle is the mother of Evonne Tuttle, a customer who was fatally shot during the botched robbery. Three of the men involved are on death row.

The group Nebraskans for the Death Penalty has also received help from the parents of Andrea Kruger, one of four people killed by Nikko Jenkins in Omaha 2013. Jenkins was convicted in last year but has not been sentenced.

Nebraskans for the Death Penalty has to collect at least 57,609 signatures from registered voters by Aug. 27 to place the issue on the 2016 ballot.