The scissors were in the Cardenas family's household in Bergsberg, Montana. One night in 1967, Marina Cardenas killed her husband Hector Cardenas during an altercation by stabbing him in the head with the scissors., an action which broke her right index and middle fingers and gave Hector two puncture wounds on the top left side of his head. Their adopted younger son Francis made the scissors disappear via his reality-editing powers, transporting them into the house within the house pocket dimension.
When Francis created the land of Wendimoor soon after, the scissor murder incident had an influence, leading to scissors being cast as a deadly weapon in that dimension: scissor swords and giant scissors being used for executions by the Dengdamors.
Fifty years later, Dirk Gently found the scissors in the house within the house pocket dimension, in a duplicate of the house's kitchen, stuck into the kitchen table which continuously bled from the stab hole. Dirk pulled it out of the table to defend himself against the Purple People Eater, and took it with him when he left the pocket dimension. Presuming it was the murder weapon, Dirk handed the scissors to Sheriff Sherlock Hobbs. A comparison with the holes in Hector Cardenas' skull at the Bergsberg County Sheriff's Department confirmed the likelihood of the scissors being the murder weapon, although their apparent newness and the fresh bloodstains were found puzzling.