Charges have been dismissed against a Prior Lake couple a year after they were charged with helping their son and his friends make pipe bombs that were planted in south-metro mailboxes, and the couple are blaming sloppy police work -- or worse -- for implicating them in the first place.

The parents were accused of buying materials and knowingly helping the boys make the bombs in an "educational" prank. But now there's not evidence to support those allegations, officials concede.

Bob and Robbie Masters and their attorney Earl Gray claim that Burnsville police officer Patrick Gilligan, who was investigating a mailbox bomb in his city, wrote inconsistent reports, lied and took statements out of context. They say he had a vendetta against Robbie Masters because she told teens to not talk to police without their parents present.

Burnsville police officials adamantly denied those allegations.

"Officer Gilligan is an excellent officer -- to attack him is concerning," Capt. Eric Gieseke said.

Officers are not available to comment publicly when they are accused of misconduct, a police spokesman said. Burnsville Police Chief Bob Hawkins was out of town and could not be reached for comment.

"It was a professional police investigation, and we support the officer's investigation. We stand behind the officer's character, and there was no vendetta," Gieseke said. "The officer acted in good faith and tried to report the incident as accurately and as correctly as he possibly could."

Burnsville police said there is no internal investigation involving the officer, who has never before faced discipline.

Ron Hocevar, Scott County chief deputy attorney, said it became clear while preparing for the trial that there was not enough evidence to prove the crimes beyond a reasonable doubt, so the charges were dismissed on Tuesday "in the interest of justice."

'Living in another world'

The Masterses had been charged with aiding an offender and possessing or manufacturing explosive devices, and they could have faced prison terms.

"It was like we were living in another world, like 'The Twilight Zone': Is this really happening?" Robbie Masters said Thursday.

According to the charges filed against the couple, their son, 17, and other teens had planted the bombs in mailboxes in Burnsville, Lakeville, Credit River Township and New Market Township in May and June 2009. In one case, the Bloomington bomb squad was called to remove a 6- to 8-inch pipe bomb.

But Hocevar said that as he reviewed transcripts of the officer's recorded interviews while preparing for trial, he realized that the interviews with the seven teens in the case suggested that the couple knew their son, Travis, was making smoke bombs, but there was no evidence that they knew he and his friends were making pipe bombs.

All the teens have pleaded guilty and have received sentences, including community service.

Crying foul for months

The dismissals came one day shy of a year after the charges were filed, Bob Masters said.

Gray said he had been pushing for months for dismissal by pointing out inconsistencies in the officer's reports. Bob Masters said he doesn't understand why prosecutors took a year to look at the transcripts.

The transcripts, filed in Scott County District Court, do not jibe with the officer's written report, which says the parents knew what was going on with the pipe bombs. The transcripts show, in fact, that one boy said he kept Bob Masters busy playing chess so he wouldn't discover the boys were making pipe bombs instead of smoke bombs in the garage.

"This infuriates me to no end for two reasons," Masters said. "One, a punk cop can pull lines out of context, put periods where commas belong and cause this type of a thing to drive forward. He can do it simply because he doesn't like the idea that the Constitution allows a woman to demand her rights when talking to him."

And secondly, he said, it shows "a lazy, bureaucratic, cover-your-butt system that has attorneys working for the county, dragging their feet," and running up the Masterses' legal bill to about $50,000.

"All they had to do was read this stuff. All they had to do was look at the transcripts of the boys saying, when answering the question, 'Did Travis' parents know you were building bombs?' And the boys answered, 'Yes, we knew they were building bombs -- but not explosives, smoke bombs.' And every one of them said it," Bob Masters said.

Masters said that in January, he was questioned by the FBI and federal Bureau of Alcohol, Tobacco, Firearms and Explosives at the freight transportation company where he's a vice president. The firm is an air freight forwarder, he said, and the agents said they were concerned about terroristic acts.

While the federal agents were polite, he said, "they told me that they were coming to see me because they needed to know if I was an anti-government white supremacist."

Staff writer Rochelle Olson contributed to this report. Joy Powell • 952-882-9017