BANGOR — Jurors could not decide if a former Prentiss Township man torched the car of a state fire marshal who was investigating a string of arsons and graffiti taggings around the man’s isolated cabin.

“I’m declaring a mistrial as to that particular count,” Superior Court Justice William Anderson said at the conclusion of the five-day trial Friday at the Penobscot Judicial Center against John A. Weckerly.

Weckerly, 54, will remain free on bail awaiting his retrial on the arson charge. He was indicted by a Penobscot County grand jury in April 2012 on a dozen charges — four counts of arson, five counts of criminal mischief and one count each of aggravated criminal mischief, burglary and theft by unauthorized taking.

After deeming a deadlock in deliberations about the arson to Fire Marshal Sgt. Timothy York’s state vehicle two years ago, the jury of seven women and five men found Weckerly not guilty on the 11 other charges.

“I don’t know what else we could have done,” Penobscot County District Attorney R. Christopher Almy said with obvious frustration in his voice after leaving the courtroom Friday.

Weckerly was arrested without incident and charged with arson early on Aug. 3, 2011, after a state police dog followed a scent from the fire marshal’s destroyed car to Weckerly’s home about half a mile away, the prosecutor said last week.

York and two other fire investigators were on a midnight detail investigating three previous arsons in the area.

The car was set ablaze with a flammable liquid, and a bucket of gasoline was found on the roadway leading to Weckerly’s home. Gloves covered with gasoline were found hanging in his shed, the prosecutor said.

The jury deliberated for four hours Thursday and for several hours Friday before returning their verdict. Their decision was announced at noon.

Defense attorney Kirk Bloomer of Bangor said during the trial that the evidence did not connect Weckerly to the crimes. He declined to make a comment afterward, but Weckerly said he was pleased with the jury’s decision.

“That was good,” he said on the front steps of the courthouse. “I never went through anything like that.”

Weckerly said the mistrial was a “definite victory.”

“I don’t think there is any possibility of them convicting me of setting the car on fire,” he said.

Almy said the state will have to review the case before a decision is made about retrying the case. If the decision is made to go forward, a second arson trial would be scheduled for later this year or early next year, he said.

“I keep going over this again and again,” the prosecutor said. “We did everything we could possibly think of and to that extent, I’m frustrated.”

Weckerly, who has been staying in Bangor as part of his bail conditions, added that he was disappointed that he doesn’t get to return home to Prentiss Township. Bloomer requested that his bail be modified to allow him to return to his rural cabin, now that he has been acquitted of 11 of the 12 charges, but Anderson denied his request.

“We are still concerned about him,” Almy said.