But this week's allegations aren't the first time someone has raised concerns about how the unit handled cases during the same period. The issue surfaced about 18 months ago under the administration of now-retired chief Thayle "Buzz" Nielsen.
Russo said the director of the Children's Justice Center of Salt Lake County called police administrators then to report a "slack on quality" in an investigation. Russo, who was hired by the city in August to replace Nielsen, said that an ensuing investigation found that in many instances, domestic violence/sex crime unit detectives were waiting months to follow up on allegations filed in initial complaints by patrol officers.
The probe also determined that detectives were using their own judgment to decide whether to close cases rather than presenting them to the Salt Lake County district attorney's office, Russo said.
"Since then," Russo said, "we have repaired relationships and been able to make sure to the satisfaction of the Justice Center that we are appropriately handling the cases."
When reached at his home Wednesday morning, Nielsen said there is usually a backlog with those types of crime. However, he said, he wasn't aware that anyone had raised concerns about how the unit was operating and wasn't familiar with last year's internal probe.
"I can't remember anything coming across my desk like that," he said.
Russo, though, said that as a result of the internal probe, Nielsen transferred all the officers, including the supervisor, out of the unit. No disciplinary action was taken or formal write-ups about the incident made.
"They met with [Nielsen], and they decided they'd handle it administratively through transfers," Russo said his staff told him. "[This was] certainly something where better attention needs to be paid. The supervisors involved were moved out of their assignments."
Russo said new detectives were transferred in, and resources were added to catch up the caseload.
Nielsen said transfers would have been handled at a division level, and no proposed disciplinary action was ever presented to him.
District Attorney Sim Gill said he was not aware of any potential issues with the sex crime unit's cases.
"Obviously, if they never presented it to us for screening, we never had a chance to see it," Gill said. "So we wouldn't know of its existence."
After the discovery that cases were not being screened, Russo said, the department instituted a new policy that cases must be screened by the district attorney's office.
Gill said that, in general, he prefers that all police departments screen person-on-person crimes with his office. Other crimes are usually done at the discretion of the respective agencies, he said.
"I think the higher the category of the person-on-person injury, the more it ought to be looked at," he said. "I think [screening] is important. It's a good way to get feedback, to get direction, to get clarity."
In the past year, his office dismissed more than 110 cases linked to the city's Neighborhood Narcotics Unit, which faced its own issues for mishandling evidence, illegally using GPS devices and keeping suspects' property as trophies.
Gill also said that, in general, when allegations are raised that cases aren't being investigated, it's "troubling."
"I find it troubling for our victims," he said. "I find it troubling for our community that is calling with an expectation of aid."