‘Today is the day’: Missouri teenager allegedly told investigators he killed his grandfather for poisoning him

A Missouri teenager is in custody after he allegedly shot his grandfather because, he claimed, the older man had been poisoning him, prosecutors said.

On Aug. 1, Mastin Paul William Raines, 19, allegedly gunned down his grandfather, 55-year-old William Mark Gustin, who suffered fatal wounds to his neck, shoulder and stomach, at a Centerville home.

A deputy from the Johnson County Sheriff’s Office, responding to a report of shots fired arrived at the scene and overheard Raines making a vow, Kansas City’s WDAF-TV reported, citing court documents.

“He will never do it again,” Raines allegedly said.

The deputy asked what he meant, and Raines, according to the documents, responded: “My grandfather, he’ll never do that again.”

Court documents state Raines allegedly also said that “today is the day” his grandfather would die for poisoning him, according to KSHB-TV.

Raines told investigators he loaded a 30.06 rifle and then drank alcohol so he could get the courage to shoot his relative, the legal documents claim. The teenager allegedly said he and Gustin were sitting on the couch when he shot the older man in the stomach.

A witness in the home at the time of the incident said she heard the gunshots from the kitchen and hid in a bathroom. WDAF-TV reported the witness said Raines allegedly admitted to the shooting and gave her the firearm.

Raines has pleaded not guilty to a second-degree murder charge. He is being held without bond, Johnson County Sherrif’s Office online records show.