PITTSBURG — Fifteen defendants, including one who served almost 250 days in jail, had their criminal convictions dismissed this week after prosecutors and public defenders agreed that the Pittsburg Police Department failed to disclose information about prior misconduct on the part of police officers involved in the cases.

The agreement between the Contra Costa District Attorney’s Office and Public Defender’s Office is the culmination of months of challenges by defense attorneys after this newspaper reported on the police department’s failure to comply with so-called Pitchess motions. Pitchess motions are common legal requests for records of officer misconduct lodged by defense attorneys in criminal cases.

Former Pittsburg police Lt. Wade Derby filed a lawsuit earlier this year alleging he had warned the department and gave memos to Chief Brian Addington alerting him that the department needed to turn over the records on officers Michael Sibbitt and Elisabeth Ingram for beating suspects with flashlights.

“Reading between the lines, these cops were problematic and their information should’ve been disclosed way back when,” deputy public defender Diana Garrido said. “It would’ve had an impact on their cases.”

The Contra Costa District Attorney’s Office said in a statement that three cases involved felonies including commercial burglary, unlawful taking of a vehicle, possession of stolen property, and gun possession by a felon. Ten cases involved misdemeanors, including petty theft, resisting arrest, providing false information to police and drug possession. Two cases involved infractions. The allegations against the Pittsburg officers occurred about spring 2014, and they were involved in these criminal cases up until last year.

Defense attorneys typically seek information about prior misconduct by police officers in order to challenge the officers’ credibility in an ongoing case, or show patterns of behavior. Once that information is produced, prosecutors may decide that a particular officer is so tainted he should not testify, or jurors may decide to disbelieve testimony because of the past misconduct.

The longest sentence among the dismissed cases involved Carl Schoppe, who was convicted of being a felon in possession of a firearm and sentenced to 16 months in state prison; he was released after serving 245 days in County Jail, according to Garrido. Of the other affected defendants who received County Jail sentences, the longest was 180 days, according to the district attorney.

“They are very relieved and extremely pleased that they’ve been vindicated,” Garrido said.

Schoppe’s original Pitchess hearing was held Sept. 17, 2014. The police department brought no records on Ingram, who participated in the Schoppe investigation, according to the public defender motions. Police departments routinely share such personnel files with judges who determine whether the material is applicable to the specific case.

Pittsburg police did not immediately return a request for comment.

The cases were dismissed in an agreement between prosecutors and defense attorneys before it was determined whether police purposely hid the documents or inadvertently failed to turn them over, as Pittsburg officials have claimed.

“No matter how you categorize (the police misconduct documents), if evidence of officers involved fabricating evidence or other misconduct, they should be brought forward in a Pitchess motion,” Garrido said.

Earlier this year, this newspaper also reported on Pittsburg police falsifying police reports to lower crime stats and hiding police personnel records from court cases. Those allegations were also prompted by Derby’s lawsuit.

Ironically, the two former officers whose misconduct files were not turned over to defense attorneys filed their own lawsuits in August. Sibbitt and Ingram claim they were instructed to falsify crime reports and refrain from documenting use of force — all to provide a rosier picture of the city’s safety.