The family of Michael Brown has filed a wrongful death lawsuit against the city of Ferguson, Mo., seeking unspecified damages and police reforms after the black teen’s killing by a white policeman prompted a national debate on law enforcement and race.

The civil lawsuit filed April 23 in St. Louis County, Mo., names the city of Ferguson, former Police Chief Thomas Jackson and former police officer Darren Wilson as defendants.

The lawsuit seeks $75,000 in compensation, as well as unspecified punitive damages, and calls for a court order prohibiting the use of police techniques “that demean, disregard, or under serve its African-American population.”

The shooting last August sparked protests and a national movement questioning police use of deadly force, especially against minorities in cities around the country.

The lawsuit alleges that Mr. Wilson destroyed evidence after he shot Mr. Brown on the street of the St. Louis suburb last August, saying he washed blood off his hands and cleared and bagged the gun used in the shooting.

“We expect to put on evidence that you never heard about before, that you have never seen,” Anthony Gray, one of the lawyers for Mr. Brown’s family, said at a news conference to discuss the lawsuit.

Mr. Gray said evidence had not been presented properly in the previous investigations.

A grand jury in Missouri decided last year not to bring criminal charges against Mr. Wilson. The U.S. Department of Justice later cleared the police officer of any civil rights violations.

“Because it is pending litigation, the city won’t be able to make any comment,” Jeff Small, a spokesman for Ferguson, said in a telephone interview.

The city previously said it would establish a citizen review board, diversify recruitment of police officers and put into ef- fect use of body cameras by police officers and add dashboard cameras to patrol cars.

Lawyers for Mr. Wilson were not immediately available to comment.

The lawsuit has been expected since last month when the family expressed disappointment in the Justice Department investigation and said it would sue.

The department’s report did find racial bias and a pattern of illegal actions against African-Americans by the Ferguson Police Department.

Mr. Jackson resigned as police chief in March within days of the report’s release.

The lawsuit lists incidents of alleged unlawful stops and ar- rests of African-Americans in Ferguson. It asked for the court to assign a monitor to the city’s police force for five years or until “the city of Ferguson has fully and effectually trained all of its police officers on the constitutional requirements of the use of deadly force.”