Lawyers for the parents of an unarmed, black 18-year-old who was fatally shot by a white police officer in a St. Louis suburb say they will file a civil lawsuit Thursday against the city of Ferguson.

Attorneys for Michael Brown's family announced in a statement Wednesday night their plans to file the lawsuit.

The lawsuit had been expected. Attorneys for Brown's mother, Lesley McSpadden, and his father, Michael Brown Sr., said at a press conference in early March that a wrongful death lawsuit would be filed "soon."

Brown's shooting death in August by Officer Darren Wilson led to sometimes-violent protests that were renewed when a grand jury declined to charge Wilson.

The U.S. Justice Department also declined to prosecute Wilson, who resigned in November.