A woman "slapped" the back of a police car shortly before an Australian woman was shot dead by an officer, according to a search warrant.
The search warrant, filed by the Minnesota Bureau of Criminal Apprehension and obtained by Minnesota Public Radio, does not specifically say that the woman was Justine Damond, but "upon police arrival, a female 'slaps' the back of the patrol squad ... After that, it is unknown to BCA agents what exactly happened, but the female became deceased in the alley".
News of the warrant came hours after personnel records for the policeman who shot Ms Damond, 40, in Minneapolis were released publicly on Monday.
The records provided some detail about the training courses he took but no insight into his on-the-job performance.
The records show Officer Mohamed Noor was hired as a cadet in March 2015.
In September that year, he received a letter saying he passed his Peace Officer Licensing Examination and was eligible to become a licensed, sworn officer.
The records also show he took multiple training courses, including recent in-service training about active shooter situations during the Super Bowl, which will be held in Minneapolis next year.
His file also says he passed all of his annual semi-automatic, handgun and shotgun qualifications, but there are no additional details about how he performed.
Officer Noor is on paid leave after he killed Ms Damond, a spiritual teacher who was engaged to be married, on July 15, after she called 911 twice to report a possible rape.
Officer Noor, who was in the passenger seat of a squad car, shot across his partner in the driver's seat and the bullet hit Ms Damond.
His partner told authorities that he was startled by a loud noise shortly before Ms Damond appeared at the police vehicle.
The search warrant did not say whether the slap was the loud noise Officer Noor's partner described, MPR reported.
State authorities are investigating potential criminal charges and Officer Noor also faces an internal use of force investigation.
Officer Noor was one of several Somali-Americans hired by the department in recent years in a diversity drive by the city to better reflect the population.
Questions about police training were raised after details about the shooting were released.
Last week, then-police chief Janee Harteau criticised Officer Noor's actions but defended his training, saying: "This officer completed that training very well. He was very suited to be on the street."
Ms Harteau resigned on Friday at the request of the mayor.
Minnesota is the only state that requires police officers to have at least a two-year degree, though many departments prefer four-year degrees.
People who want to be officers either learn law enforcement degrees, or, if they have four-year degrees in other subjects like Officer Noor, they can complete a certificate programme.
Officer Noor had a degree in economics and business administration before applying to become a police officer.
The records released on Monday do not list any awards or commendations for the officer.
Records previously released show he had three complaints against him, including one that was dismissed with no discipline and two that are pending.
The records also show that Officer Noor received a pay rise in September and is earning more than $28 an hour.