Mayor Jacob Frey and Police Chief Medaria Arradondo are scheduled Wednesday to announce a set of broad reforms in how Minneapolis investigates sexual assault, following months of work designed to improve support for victims who report attacks to police.

The new standards are based on a model policy recently devised by the state’s police oversight board, as well as a set of sweeping recommendations from a task force appointed last year by then-Attorney General Lori Swanson.

The standards also reflect months of collaboration with victim advocates, survivors and other experts in handling sexual assaults, according to an advisory issued late Monday by Frey’s office.

The new standards will be built on “compassion, accountability and responsiveness,” the mayor’s office said.

Earlier this year, the Police Department adopted several specific recommendations of the attorney general’s task force, such as assuring that people who report a sexual assault won’t themselves face charges for minor offenses, such as underage drinking. The forthcoming policy will go much further, according to Frey’s office, and appears to be a radical reworking of the Police Department’s approach to these underreported crimes.

The new policy “spells out the importance of investigators maintaining regular contact with the victim regarding the process of the investigation so that the victim does not believe it is futile or demeaning to file a report,” according to Monday’s advisory.

It also incorporates law enforcement best practices for interacting with and interviewing a victim who has been traumatized by a personal attack. Already, all Minneapolis police officers are being trained in the practice, known as trauma-informed interviewing.

The Minneapolis reforms are among several adopted by law enforcement agencies across the state in the wake of a Star Tribune investigative series, Denied Justice, which exposed widespread failings in how rapes and sexual assaults are investigated and prosecuted. All of Minnesota’s 400-plus law enforcement agencies are now required to have clear guidelines on practices for handling sexual assault reports, and the Minnesota Peace Officer Standards and Training Board, the police oversight board, created a statewide model policy that may become mandatory.

Swanson’s task force also drew up several statewide statutory recommendations that are now pending in bills before the current Legislature.