AUGUSTA – The man awaiting trial for the kidnap-murder of a Colby College student was transferred to Maine State Prison after he allegedly tried to strangle a Kennebec County Jail cellmate and threatened to attack a guard.

Edward J. Hackett, 47, was moved Tuesday to the maximum security prison in Warren following a hearing in Kennebec County Superior Court.

“Lately he’s continued to be aggressive toward staff and other inmates,” Kennebec County Sheriff Everett Flannery told the Kennebec Journal on Wednesday.

Flannery said it was difficult to isolate Hackett at the jail.

“Even in our maximum security area, they do have contact with other inmates,” Flannery said. “He was not able to get along with these people even for a short time.”

Hackett has pleaded innocent to murder and five other charges linked to the slaying of Colby senior Dawn Rossignol in September. At the time of the killing he was on parole for kidnapping and robbery in Utah and living with his parents in Vassalboro.

In an affidavit filed Tuesday with the court, Capt. Raymond Wells, jail administrator, said Hackett choked his cellmate on Dec. 18.

The following day, the affidavit said, an emergency response team was called “to extract Edward J. Hackett from his cell due to his threatening to stab with a pencil anyone who entered.”

Hackett told staff members “he has often contemplated using the handles of cleaning instruments to ‘take out an officer,”‘ Wells said.

Hackett is being held in the Special Management Unit at the Warren prison, said Francis J. Westrack, director of classification for the Department of Corrections.

Westrack said transfers in cases like Hackett are unusual but not unique.