(Minneapolis, MN) — According to multiple sources, the U.S. Attorney’s office has convened a federal grand jury to investigate the killing of two Burnsville Police Officers and a firefighter/paramedic during a domestic disturbance response in February. On Tuesday, the mother of three of Shannon Gooden’s children testified before the grand jury. The focus of her testimony is believed to be on how Gooden obtained the firearms used in the shooting. Gooden was prohibited from possessing firearms due to a 2008 conviction for second-degree felony assault with a deadly weapon. The purpose of the grand jury is to determine if there’s sufficient evidence for criminal charges. If warranted, the grand jury may issue an indictment. While grand jury proceedings are confidential, individuals subpoenaed can disclose information about their testimony.