SCOTTSDALE, AZ — A newly released report into the on-duty death of a Scottsdale police officer reveals the rifle that fired had its safety off when it fell out of a backpack and discharged.
Mesa Police Department’s Homicide Unit conducted the review into Detective Ryan So’s death at the request of Scottsdale police. The report “found no evidence of criminal negligence on the part of any parties.”
Detective So and another detective – whose name was redacted from the publicly released report – had returned to a department facility after serving a search warrant on the evening of June 13.
The report says the other detective’s vehicle was having “electrical issues” so he planned on switching out vehicles. Detective So offered to help the detective move things out of the vehicle.
Detective So removed a backpack from the vehicle, grabbing the pack by its metal frame and holding the pack upside down. He took a few steps. A rifle fell out from the bottom of the bag, butt stock first, striking the asphalt and discharging. Detective So collapsed.
A police sergeant who was nearby heard a loud gunshot and initially thought someone accidentally or unintentionally discharged a gun. He saw Detective So on the ground and called for medics and additional police units. Police began checking neighboring businesses for a possible ambush shooter because it was still unclear how the injury occurred.
The 38-year-old So was rushed to the hospital where he later died. He was a nine-year veteran of the Scottsdale Police Department and left behind a wife and three children. The Maricopa County Medical Examiner later ruled his death accidental, saying he died of a gunshot wound to the neck.
The backpack and rifle that discharged were not So’s, according to the Mesa report. They were issued to the other detective, whose name is redacted, and was only used by him, he told Mesa police in an interview. The report says the detective was "visibly upset," when initially interviewed about what happened that night.
The rifle that discharged was an Accuracy International .308. Investigators found 10 live rounds in the magazine and one fired casing in the chamber. The detective told police the rifle was last used about a month earlier in a training exercise in California.
In an interview, the detective told Mesa police it is standard practice to store the rifle with the chamber empty and the safety on.
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“Detective (name redacted) had stated his standard practice is to keep the safety lever on full safety, although he did not have specific recollection of this when he last stored the rifle in May,” the report said.
Mesa police conducted forensic testing to determine if the rifle could discharge if dropped. They determined the rifle was capable of discharging if cocked with the stock folded closed and the safety in the ready-to-fire position and dropped butt first.
Mesa said its investigation is now closed.
Mesa is one of three agencies investigating Detective So’s death.
Earlier this year, a report by the state’s worker-safety agency, the Arizona Division of Occupational Safety and Health (ADOSH), found no state or federal safety violations.
But ADOSH officials also acknowledged there may be internal policies within the Scottsdale Police Department related to gun storage and ammunition that are outside ADOSH jurisdiction.
Scottsdale police are still conducting an internal investigation into whether department policies were broken. Scottsdale police said they don’t have an estimate for when that review will be complete.
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