The fatal accident took place in front of her relatives during a family dinner for Mother’s Day on Sunday at a resort in Phrae.
Mae Hong Son Senator Boonsong Kowawisarach, 56, was removing ammunition from his gun when it suddenly discharged, shooting his 46-year-old wife Chanakarn Dedkhad in the abdomen.
She died on her way to hospital.
Wang Chin Police Station received the report on the shooting at 10pm on Sunday.
Police will submit a letter to the Senate president for permission to prosecute Boonsong, who is now protected by parliamentary immunity.
“At this point, he is charged with reckless action causing the death of another person,” Phrae police chief Maj General Wisut Wongkham said.
Chanakarn’s relatives said they have no intention of taking legal action against Boonsong because they believe it was an accident.
An informed source said Boonsong was partially paralysed and his condition could be a reason for the accident.