A Baltimore homicide detective fatally shot last week was killed a day before he was due to testify in a high-profile racketeering case against several fellow officers, authorities said Wednesday. Baltimore Police Commissioner Kevin Davis said Detective Sean Suiter was scheduled to testify before a federal grand jury in a case against eight former members of the city’s elite gun task force accused of shaking down city residents and conspiring with drug dealers. Authorities do not believe Suiter was killed over his expected testimony, Davis said, adding that he was shot spontaneously when investigating a report of a suspicious person. Suiter was believed to have been killed with his own service weapon at close range following a struggle, Davis said. An 18-year veteran of the force and a married father of five, Suiter was shot once in the head last Wednesday and he died a day later, the day he was expected to testify.