During the 911 call obtained by The Tribune through an open records request the woman told the dispatcher that the baby's father had tried to shoot himself and she can be heard telling someone, "You give me that gun."
Moments later, with the gun in the grandmother's hands, and Ryker in his father's arms, the woman told the dispatcher that she thought the 5-month-old had died, but then said he began breathing again.
"Ryker, Grandma's here," the woman said. "Ryker, Grandma loves you with all my heart."
Throughout the phone call, a muffled male voice can be heard in the background, and when the woman asks the man why he did this, his voice can barely be heard in the background: "I wanted [inaudible] together."
Ryker was pronounced dead at a Salt Lake City hospital.
Petersen has since been charged in 4th District Court with aggravated murder, a first-degree felony. If convicted, Petersen could face the death penalty or up to life in prison. Whether prosecutors will seek the death penalty will be decided after Petersen is arraigned.
Petersen appeared in the Provo courthouse Monday, where he was supposed to decide whether to waive his right to a preliminary hearing. His attorney asked for a continuance, and another hearing was set for May 20.
If Petersen opts to have a preliminary hearing, prosecutors will present evidence to a judge, who will then decide if there is enough evidence for Petersen to stand trial on the aggravated murder charge.
During a bail hearing in April, American Fork Sgt. Gregg Ludlow said Petersen had been planning to kill the child for about a month. Ludlow said during the hearing that Petersen told police he took the child into the basement of his home and placed him on a couch. He went into another room, loaded a single round into a .22 caliber rifle, went back into the room and shot the infant in the forehead, Ludlow said.
Police said a relative stopped the man before he turned the gun on himself.