BOULDER, Colo. (CBS4) – Prosecutors believe a veteran Boulder detective tipped off a suspect in an Internet luring and sexual exploitation sting.

Court records say Detective Jack Gardner, 56, advised the suspect to cease communication with who he thought was a 13-year-old girl because Gardner was upset he wasn’t more involved in a police case.

Boulder police arrested Gardner on suspicion of accessory to Internet luring, official misconduct and obstructing government operations.

Kahlil Peckham, the man suspected in the sting, faces Internet luring and sexual exploitation charges. Police said he was preparing to meet a purported girl from Connecticut — who was actually an undercover officer — after he responded to an ad police placed on Craigslist in May. He allegedly sent hundreds of sexually explicit texts and other digital messages.

The Jefferson County District Attorney’s Office is prosecuting the case.

Court records indicate that on June 5 someone warned Peckham, 26, against going forward with the meeting.

About a week later, Boulder police searched Peckham’s home after obtaining a search warrant and discovered the warning came from within the Boulder Police Department.

Police then asked the Jefferson County DA to help with the case. Eventually it was determined, according to court documents, that the warning came from Gardner.

Gardner, a 16-year veteran of the department, posted bond Thursday. His department has placed him on unpaid administrative leave. He is scheduled to appear before a judge on Oct. 8.

Peckham was scheduled to appear before a judge on Friday afternoon. He is in custody under a $50,000 bond.

Court documents don’t specific why Gardner may have wanted to warn Peckham against a meeting with who he thought was the teen. But an arrest affidavit states Gardner was upset he was excluded from the police plans at one point.

It states: “Detective Gardner was inadvertently excluded from the operations plan that was developed on June 4th” and that his partner in the Internet Crimes Against Children division “stated … that Detective Gardner was upset that he was excluded from the operation.”

That partner said he “had apologized to Detective Gardner about the unintentional oversight and he considered the issue resolved.”

“No one is above the law,” Peter Weir, the Jefferson County District Attorney said. His office has been assigned to prosecute Gardner’s case. “There might have been some hard feelings on the part of Detective Gardner that he wasn’t integrally involved in the investigation itself, that he had been excluded to some extent from the investigation.”

Officials said they haven’t found a connection between Gardner and Peckham, other than this case.

“We have a responsibility to be accountable to our residents and we understand the trust the public gives us to protect our community,” Boulder Police Chief Greg Testa said in a statement.

Boulder Police Chief Statement

The following is the complete statement from Boulder Police Chief Greg Testa about this case.

The Boulder Police Department is conducting an internal personnel investigation into allegations of misconduct by an officer.

The internal investigation has been conducted concurrently with a separate criminal investigation involving Detective Jack Gardner, who turned himself into the Jefferson County Detention Center on Sept. 25, 2014 pursuant to an arrest warrant.

Detective Gardner was arrested on suspicion of Accessory to Internet Luring (Class 5 Felony), First Degree Official Misconduct (Class 2 Misdemeanor) and Obstructing a Government Operation (Class 3 Misdemeanor) in connection with a Boulder police investigation in which a suspect was warned about an undercover investigation that targeted that suspect.

When Boulder police discovered that the suspect had been warned, we began an investigation into the warning. Based on that investigation, it’s alleged that Detective Gardner sent the warning. I initiated an internal personnel investigation and contacted the Boulder County District Attorney’s Office to request a separate criminal investigation by their office.

District Attorney Stan Garnett referred the investigation to the First Judicial District Attorney’s Office (Jefferson and Gilpin Counties) because of the close working relationship between the Boulder County District Attorney’s Office and the Boulder Police Department. The Boulder Police Department has been working cooperatively with investigators from the First Judicial District.

Detective Gardner was placed on paid administrative leave on July 9, 2014, as per police department policy and contractual due process. Subsequent to his arrest on criminal charges, Gardner was placed on unpaid administrative leave pending the outcome of the internal personnel investigation. The internal investigation is focusing on whether Gardner may have violated department rules, policies or procedures and is separate from the criminal investigation.

Once the internal personnel investigation has been completed, a review panel made up of both citizens and department members will provide recommendations to the police chief regarding the final disposition of the case. The allegations, if sustained, could result in serious discipline, including possible termination from the Boulder Police Department.

We take these allegations seriously and notified the Boulder County District Attorney’s Office immediately. In addition, we are conducting a thorough internal investigation into the matter. We have a responsibility to be accountable to our residents and we understand the trust the public gives us to protect our community.

Detective Gardner is presumed innocent and is entitled to due process during these proceedings.

At this time, no further information will be released. We will notify the public once the internal investigation and review process has been completed. The Boulder Police Department cannot comment on the separate criminal investigation which is being conducted by the First Judicial District. Any questions regarding that investigation should be directed to the First Judicial District.