RIVERTON, Wyo. (AP) — Prosecutors in the case of a man accused of fatally shooting his wife in front of the couple's children on the Wind River Indian Reservation have asked for a continuance so they can prepare for a possible self-defense claim.

Prosecutors say if Koby Johnson uses a self-defense and accidental shooting defense, than they will need more time for the FBI to analyze evidence. The trial was previously scheduled for April 11.

Johnson is accused of the Nov. 21 shooting of 36-year-old Rachael Noel Johnson.

Federal Bureau of Investigation agents said Johnson shot his wife over an argument about pain medication. They say the shooting took place in front of some of their children, who range in age between four months and 13 years.