It was wise of Spokane Mayor Dennis Hession to call for an outside investigation into the case of Otto Zehm, who had a fatal encounter on March 18 with seven police officers. This week’s release of the Police Department review of the encounter confirms that. So does the lack of curiosity by the county prosecutor.

The seven-page report written by Detective Terry Ferguson was submitted to Spokane County Prosecutor Steve Tucker on May 31, and it recommends that no criminal charges be brought against any of the officers. It also concludes that Senior Officer Karl Thompson, who was first on the scene, was justified in striking Zehm with his baton to pre-empt an expected attack.

The final determination on those matters appropriately lies with others, but some of the decisions on what to exclude from the report are troubling.

Ferguson notes toward the end of the report that her conclusions were based on interviews with officers, witnesses, Zehm’s employers and mental health professionals, plus the 911 tape, police radio transmissions and a review of the security video. But in describing the scuffle, she never alludes to the video or explains apparent discrepancies between what it shows and her conclusions.

For instance, in the initial encounter between Zehm and Thompson, she notes the 2-liter Pepsi bottle that Thompson said Zehm was carrying. She doesn’t mention that the bottle is not visible on the video. She doesn’t mention whether police have a bottle with Zehm’s fingerprints on it. She doesn’t say why the video should be dismissed.

A glaring omission from the report is the mask that was placed over Zehm’s mouth and nose three minutes before he stopped breathing. Officer Erin Raleigh is very clear about that in his report: “Upon placing the mask on Zehm, he immediately began to react and scream and yell. I observed as Zehm began to violently move his head and lower torso back and forth in what appeared to be an attempt to remove the mask.”

Raleigh then details how officers tried to regain control of Zehm: “After a very short time, Zehm began to relax and calm himself on the floor. Zehm still had the mask on his face and had stopped screaming.” Shortly thereafter, Raleigh noticed that Zehm’s breathing “began to fade.”

Police files show that the mask made a big enough impression on Ferguson that she called a forensic specialist, who found it in a trash bin. So why did she leave it out of her report? She doesn’t say.

Furthermore, Spokane County Medical Examiner Sally Aiken didn’t mention the mask when she announced the cause of death. It could be in her report, but she and the Police Department have refused to release it.

The public ought to be concerned that authorities have never voluntarily mentioned the mask. The public ought to be concerned that the mask may never have come out if not for a reporter’s question during a showing of the video. The public ought to be concerned about how this case would have been handled if the scuffle had not been captured on video.

The public certainly can’t take solace in the actions – or lack thereof – from County Prosecutor Tucker, who indicated this week that he had yet to fully watch the video, even though it’s shorter than an episode of “Law and Order.” He cited that stunning lack of curiosity in saying that he needed another week before determining whether he will bring criminal charges.

To reiterate, it’s a good thing the mayor has called for an outside investigation, because the current one can’t be trusted.