Lawyers for the parents of Michael Brown, the unarmed, black 18-year-old who was fatally shot by a white police officer in a St. Louis suburb, announced Wednesday night that they planned to file a civil lawsuit the following day against the city of Ferguson.

Attorneys for the family said in a statement Wednesday night that the wrongful death lawsuit would be filed Thursday.

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

Attorneys said at the time that the lawsuit would also name former Officer Darren Wilson, who shot Brown. The statement Wednesday did not mention Wilson, and a spokesman for the law firm said he could not provide any additional information about the lawsuit.

Brown's shooting led to sometimes-violent protests and spawned a national "Black Lives Matter" movement calling for changes in how police deal with minorities.

A St. Louis County grand jury and the U.S. Justice Department declined to prosecute Wilson, who resigned in November. But the Justice Department last month released a scathing report citing racial bias and profiling in the Ferguson Police Department and a profit-driven municipal court system that frequently targets black residents.

Several city officials resigned following the review, including the city manager, police chief and municipal judge. The municipal court clerk was fired for racist emails.