Flowers, candles and mementos sit outside one of the makeshift memorials at Marjory Stoneman Douglas High School in Parkland, Florida on February 27, 2018.
CNN  — 

More than a dozen families for the victims of the Parkland, Florida, high school massacre have reached a settlement with the Justice Department in connection with a lawsuit they filed after the FBI failed to act on tips warning about the shooter, according to a court filing on Monday.

After three years of litigation, “the parties hereby advise the Court that they have reached an agreement to settle all of the claims at issue,” according to the joint notice of agreement to settle the federal lawsuit filed on Monday. The Justice Department will pay $127.5 million to the families, according to a source familiar with the case.

On Valentine’s Day 2018, Nikolas Cruz entered Marjory Stoneman Douglas High School and murdered 17 students and faculty members and injured 17 others. According to the lawsuit, the FBI received tips about Cruz’s violent behavior, mental instability, and a large purchase of firearms, yet failed to intervene.

Cruz pleaded guilty to the shooting in October and faces the death penalty in an upcoming sentencing hearing.

Kristina Infante, lead counsel for the plaintiffs, said in a statement that while the financial details are currently confidential, it is an “historic” settlement and “the culmination of the Parkland families’ long and arduous efforts toward truth and accountability.”

“It has been an honor to represent the Parkland families who, through their immeasurable grief, have devoted themselves to making the world a safer place,” Infante said. “Although no resolution could ever restore what the Parkland families lost, this settlement marks an important step toward justice.”

The Justice Department declined to comment beyond the filing.

In a motion filed in October, the Justice Department said that the families’ “causation theory is based on pure speculation that special agents in the Miami Field Office would have been able to prevent Cruz from committing his heinous act. Not only is such a theory speculative, but it necessarily relies on an impermissible stacking of inferences regarding how an investigation would have led to the prevention of the crime.”

In a separate lawsuit, more than two dozen survivors of the massacre and families of the victims reached a $25 million settlement in October against the Broward County School Board. The agreement will not include any admission of wrongdoing by the school board, David Brill, an attorney in that lawsuit, told CNN.

This story has been updated with additional reporting Monday.