An attorney representing the family of the National Grid worker struck and killed at a construction detail in Waltham says a civil lawsuit in the case against the driver is “imminent.”

Roderick “Kito” Jackson’s family is in the midst of appointing of a personal representative for their son and brother’s estate, and they expect the process to be done in the “coming days,” said Thomas Flaws, of Boston-based Altman Nussbaum Shunnarah Trial Attorneys.

“Once established, the family plans to file a lawsuit immediately and begin the search for answers on how this senseless tragedy could have taken the life of their beloved Kito,” Flaws said in a statement Thursday afternoon.

Flaws’ statement came just hours after a Waltham judge ordered suspect Peter Simon, 54, of Woodsville, N.H., remain behind bars without bail for 120 days.

Jackson, a gas technician for National Grid, a company the 36-year-old Cambridge resident had worked for since 2021, died on the job Dec. 6 when Simon allegedly crashed into him at the construction detail.

Jackson died alongside Paul Tracey, a 58-year-old Waltham resident who worked for the city’s police department for 28 years.

“There’s nothing to say. There’s nothing to say at all,” Jackson’s sister Esmeralda Asprilla told reporters outside Waltham District Court after a judge ruled Simon a “clear and convincing” danger to the community. “We want justice for my brother, we want justice for officer Paul Tracey, and that’s it.”

The initial defendant in the lawsuit would be the driver, but they’d then follow the information and decide who else may be responsible at an institutional level, Flaws told reporters last month.

In August 2009, Simon, a former resident of Brattleboro, Vt., fled from police before crashing head on into a public transportation bus in Keene, N.H. Simon was charged with several felonies and sentenced in 2011 to five years in a psychiatric unit in New Hampshire State Prison in Concord.

Simon and the driver of the bus suffered minor injuries in the crash, while a passenger in the bus suffered injuries and was airlifted to a hospital, the Brattleboro Reporter reported at the time. Simon’s sentence was later terminated in November 2015.

Simon suffered from a “dissociative disorder” and a history of panic attacks, Cheshire County Attorney Peter Heed said at the time.

“The road to justice is not as easy as I thought,” Jackson’s mother Norma Asprilla told reporters Thursday. “We have to do a better job in our loss, for justice, for people.”

Paul Tracey’s brother, Jim Tracey, said “everybody” feels like a ball was dropped that Simon was free at the time of the incident with the suspect’s previous lengthy criminal history.

“It’s been seven weeks, and it seems like it was yesterday,” he said of the tragedy. “We’re still grieving through all of this.”

Kristin, the wife of fallen Waltham police officer Paul Tracey walks into Our Lady’s Comforter of the Afflicted Church with their children Danika and Tyler. (Matt Stone/Boston Herald)