Lesley McSpadden, mother of Michael Brown- who was shot to death by a police officer - speaks on a panel titled "The Impact of Police Brutality - The Victims Speak" at the National Action Network (NAN) national convention on April 8, 2015 in New York City

Lesley McSpadden, mother of Michael Brown- who was shot to death by a police officer – speaks on a panel titled “The Impact of Police Brutality – The Victims Speak” at the National Action Network (NAN) national convention on April 8, 2015 in New York City

*Michael Brown’s parents filed a wrongful-death lawsuit against the city of Ferguson on Thursday, beginning a new phase in the ongoing national firestorm over his shooting death by a white police officer.

Attorneys for Brown’s parents promised the case would bring to light new forensic evidence that would raise doubts about the police version of events. Some of that evidence, they said, had been overlooked in previous investigations.

Should the case make it to trial, the lawsuit could force a full review of all the evidence in the shooting and bring key witnesses to be questioned in open court, including Darren Wilson, the officer who shot Brown.

In civil cases, jurors must conclude guilt or innocence based on a preponderance of evidence, not proof beyond a reasonable doubt needed to convict in a criminal trial.

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

After the report, several city officials resigned, including the city manager, police chief and municipal judge. The municipal court clerk was fired for racist emails.