LOCKPORT – David J. Mongielo, the auto repair shop owner who has been battling the Town of Lockport’s sign ordinance for four years, was found guilty Wednesday of violating the terms of his conditional discharge on his first conviction under that law.

Town Justice Raymond E. Schilling also set a tentative trial date of July 29 for a retrial on the second sign violation charge against Mongielo. Schilling said he won’t sentence Mongielo on the conditional discharge until after the trial.

Town Prosecutor Bradley D. Marble said that because a violation of the sign law is considered an unclassified misdemeanor, the maximum sentence could be six months in jail.

Marble said Schilling was limited to giving Mongielo 15 days behind bars for violating the conditional discharge because that was the sentence Schilling suspended when he granted the one-year conditional discharge Sept. 14, 2010.

Mongielo, who is representing himself, agreed to allow Marble to introduce his first conviction as evidence against him in the upcoming jury trial.

Mongielo has an LED signboard with video capability in front of his Robinson Road business. However, the town has a law that bans any sign that changes “format” more than once every 10 minutes.

Donald J. Jablonski, a member of the Zoning Board of Appeals, testified Wednesday that he took a video of the sign Aug. 25, 2011, documenting a violation. Mongielo’s sign was flashing every few seconds between a text advertisement for a fundraising event for injured Niagara County Sheriff’s Deputy Allen A. Gerhardt and a photo of the deputy.

Mongielo told the judge that he has a copy of the tape with audio, indicating that Jablonski was talking to someone on his phone while he was shooting the video.

“I think orders were given to him to make that video,” Mongielo said. Jablonski said he was talking to his wife.

Mongielo said he wanted to subpoena Jablonski’s cellphone records and also demanded that all of his political enemies from the town Republican Party be called to testify. Schilling refused to allow that.

“I’m building motive as to why this happened,” said Mongielo, a Republican who ran unsuccessfully for town supervisor in 2009 against GOP incumbent Marc R. Smith. In 2010, Mongielo was elected to the town GOP committee but found few allies for what he considered a “reform” agenda.

Mongielo was convicted in a nonjury trial Aug. 24, 2010, of three sign violations in 2009. He was fined $750 and given a one-year conditional discharge.

In a nonjury trial Dec. 28, 2011, Mongielo was convicted on an Aug. 25, 2011, violation shown on Jablonski’s video. However, Schilling didn’t issue his verdict until March 20, 2012. Mongielo was sentenced to 15 days in jail but did not serve any time.

County Judge Matthew J. Murphy III ruled Sept. 21 that the second conviction and the finding of a violation of the conditional discharge were invalid because Mongielo should have had a jury trial and a separate hearing on the conditional discharge.

Murphy also objected because Schilling didn’t ensure that Mongielo knew the disadvantages of acting as his own attorney.