Attorney Robert Bennett, who represents the family of Justine Ruszczyk, said 35 officers were summoned by the Hennepin County Attorney's Office.
The Police Officers Federation of Minneapolis said in a news release that its members will fully cooperate in the grand jury process.
Still, Hennepin County Attorney Mike Freeman will make the decision whether to bring charges in the officer-involved shooting case, according to a statement from his office.
"Because grand jury proceedings are secret, we cannot comment on grand jury subpoenas or any testimony that occurs before a grand jury," added spokesman Chuck Laszewski.
Last July, Ruszczyk, 40, called 911 late at night to report a possible sexual assault in the alley near her home. Less than 30 minutes later, she was dead from a gunshot wound
to the abdomen, having been shot by one of the two police officers who responded to the call.
Officer Matthew Harrity told investigators that he drove to the scene and was startled by a "loud sound" near the squad car, according to Minnesota's Bureau of Criminal Apprehension. Immediately afterward, Ruszczyk approached the driver's side window, and Harrity's partner, Mohamed Noor, shot Ruszczyk through the window, Harrity said.
Noor's attorney, Thomas Plunkett, said it would be unethical and possibly unlawful to comment on the grand jury development, as proceedings will take place in secret.
"Worse, any public comment would jeopardize the fairness of an important judicial function," Plunkett said.
He said his client "continues to personally acknowledge the grief" of Ruszczyk's family and the family of her fiance, Don Damond.
Noor remains on administrative leave. Harrity has returned to duty, Lt. Bob Kroll of the police union said.
Bennett said Ruszczyk's family was very happy the county attorney was calling for a grand jury and trying to compel many officers to testify under oath.
Though the officers were wearing body cameras, they did not turn them on before the shooting, and the squad car camera did not capture the incident, investigators said.
That lack of video evidence has frustrated city officials and led the Minneapolis Police Department to update its body camera policy
to require officers to activate them upon being dispatched.
Ruszczyk's death caused outrage in the United States and Australia and led to the resignation of the city's police chief.
Though she was a veterinary surgeon in Australia, her native country, Ruszczyk worked as a spiritual healer, yoga and meditation instructor, and life coach in Minnesota.
Damond, her fiance, said the two had planned to marry in late July.