The suspect accused of plowing into a Waltham construction detail last December, killing a Waltham police officer and National Grid utility worker, has been indicted on two counts of second-degree murder and a slew of other charges.

A Middlesex County grand jury has indicted Peter Simon, 54, of Woodsville, N.H., on a dozen charges, including two counts of motor vehicle homicide, in connection to the rampage just weeks before Christmas.

The indictment comes after Waltham judge Ellen Caulo sided with prosecutors in January that Simon, who had a lengthy criminal record prior to the Dec. 6 incident, was a “clear and convincing” danger to the community.

Simon continues to be held without bail and will be arraigned in Middlesex Superior Court at a later date, Middlesex District Attorney Marian Ryan and Waltham Police Chief Kevin O’Connell said in a joint statement Wednesday.

“He is a dangerous person. He shouldn’t be out on the street right now awaiting trial,” Waltham Police Chief Kevin O’Connell told reporters outside the courthouse after a dangerousness hearing in January.

Simon is accused of running down officer Paul Tracey, 58, a 28-year veteran of the Waltham police department and Roderick Jackson, 36, a National Grid worker from Cambridge.

After allegedly crashing into the officer and utility worker at a construction site on Totten Pond Road, Simon sped away in his older model gray Ford F-150 pickup truck, colliding into multiple other vehicles before fleeing on foot, officials said.

A responding officer spotted Simon in a nearby neighborhood allegedly saying, “Police are going to kill me,” according to the report. The suspect then pulled a knife on the officer before getting into the officer’s cruiser and taking off at a “high rate of speed,” the report details.

While fleeing, Simon is said to have struck two Waltham cruisers. A pursuit then proceeded before Simon crashed in the area of 225 Winter St., where he was taken into custody.

During the January dangerousness hearing, a prosecutor highlighted Simon’s lengthy criminal history that spans decades and includes criminal charges in at least nine states.

In August 2009, Simon crashed head on into a public transportation bus while fleeing from police in Keene, N.H. Simon was sentenced in 2011 to five years in a psychiatric unit in New Hampshire State Prison in Concord but was released early in November 2015. An attorney at the time said Simon suffered from a “dissociative disorder.”

Less than a year after his release, Simon was charged with criminal threatening, driving under the influence and disobeying an officer related to a 2016 case out of Franklin, N.H.

In connection to the killings of Tracey and Jackson last December, Simon has been indicted on two counts of second degree murder; two counts of motor vehicle homicide; armed robbery; armed carjacking; three counts of assault with a dangerous weapon; larceny of a motor vehicle; four counts of operating to endanger; three counts of leaving the scene causing property damage; leaving the scene causing death; failure to stop for police; two counts of wanton destruction of property; and resisting arrest.