LARGO — A Pinellas sheriff's sergeant was suspended Monday after an internal investigation found he didn't report potential criminal misconduct by a deputy. A separate investigation into the deputy's conduct concluded that the allegations were unfounded.

Sgt. James Campbell, 48, will serve 40 hours of suspension starting Wednesday because he did not properly handle allegations that a deputy was operating a drug house and having sex with prostitutes. Campbell, who was hired in January 2002, will also face a demotion to deputy if he violates agency policy again within a year.

"He conducted this quasi-, really incompetent investigation," Sheriff Bob Gualtieri said Monday, adding that Campbell assigned a subordinate to look into the allegations.

"He should never have allowed one deputy to investigate another deputy. That's ridiculous," the sheriff said.

The Tampa Bay Times is not identifying the accused deputy because the allegations were not substantiated. Campbell was not his direct supervisor. According to Gualtieri, the allegations originated with a theft suspect.

The summary of the investigation into Campbell's conduct lays out this timeline:

Campbell, who works as a patrol sergeant, first heard of the allegations in October from a deputy he supervises. He sat on the information, waiting to receive more.

A few days later, Campbell and the deputy who told him about the allegations met with the complainant, who said he had video of the accused deputy engaging in sexual activity with prostitutes. Campbell still didn't report it.

About a week later, they met again. The complainant gave the deputy his cellphone that supposedly had the sex video on it, but they couldn't find it. The complainant then asked the deputy take the phone to his girlfriend, who also couldn't find the video.

Campbell dismissed the allegation without seizing the phone to investigate whether any data had been deleted.

They also learned during the meeting that the videos were on pornography websites, and the complainant's girlfriend provided names of the prostitutes involved. Campbell used his personal computer to try to find the video on a porn website but did not investigate further.

"I believed at that point that all these allegations were false, and I decided that there was no further need to look into it," he testified.

Campbell met with the accused deputy and told him about the allegations, which he denied.

The situation came to the agency's attention from another party, Gualtieri said. A victim of theft told the deputy who was helping Campbell that she felt he wasn't investigating her case properly. The deputy told her that he couldn't get to her case because he was tied up investigating a "crooked cop," the sheriff said.

The woman told a detective she's friends with about the situation, and he reported it up the chain of command.

Gualtieri said Campbell should have immediately notified his own supervisor and internal investigators once he learned of the allegations.

"Not only are they policy violations, but it alleged (the deputy) was engaged in criminal activity," the sheriff said. "It's very serious."

In the case of the accused deputy, Gualtieri said the agency contacted the women he's accused of having sex with. They all denied it. Investigators could not track down the phone the complainant said had the video.

Discipline records show Campbell has a checkered past, including a five-day suspension in 2009. According to Times archives, Campbell, a deputy at the time, was arrested on a driving under the influence charge in Pinellas Park with a blood alcohol level more than three times the level Florida law presumes someone is unfit to drive. Court records show he was convicted in 2010.

Both the blood alcohol level and the conviction would have resulted in automatic termination today under a policy Gualtieri enacted in 2013.

More recently, Campbell received a written reprimand in July 2016 after an investigation found he was late 97 times and left early 88 times over a five-month period while assigned to St. Pete Beach.

Gualtieri acknowledged Campbell's past but said he wanted to give him another chance. He added he did a great job working as a corporal, which led to his promotion to sergeant.

"He needs to get it right, do his job, do it competently, and do what's expected of him," Gualtieri said, "and if he deviates from that, he will be demoted, without discussion, without question."

Senior staff researcher Caryn Baird contributed to this report. Contact Kathryn Varn at kvarn@tampabay.com or (727) 893-8913. Follow @kathrynvarn.