TWIN FALLS — The Twin Falls Police Department was aware of sexual abuse allegations before hiring officer William Anthon Jansen but opted to hire him anyway after completing a “thorough background check” that included a polygraph test, police confirmed Tuesday.

Jansen, 33, of Twin Falls is accused of sexually abusing two pre-teen girls between 2005 and 2009, before he was hired as a Twin Falls cop in December 2013.

His attorney, Scott James, told a judge Monday the allegations by one of the victims surfaced during Jansen’s hiring process with the department.

“He was ordered to take a polygraph pre-hiring on whether he engaged in contact with her, and he passed that polygraph,” James said. “The allegations … were already reviewed and investigated in a … pre-employment interview and investigation by the Twin Falls Police Department. They found there was no grounds to sustain that … and they hired him as a police officer.”

Lt. Terry Thueson confirmed the department was aware of the allegations before making the hire.

“We did a very thorough background investigation,” Thueson said. “Applicants are subjected to polygraph examinations. And based on what we were able to uncover at the time, there was no reason for us not to proceed with the hire.”

Thueson said he was barred from saying more about the case because of the ongoing investigation and issues regarding disclosure of personnel information.

Jansen was placed on paid administrative leave during the recent criminal investigation and switched to unpaid leave when the charges became formal Monday, Police Chief Craig Kingsbury said.

Jansen is charged with touching the genitals of two pre-teen girls.

“Bill completely and categorically denies these baseless allegations,” his attorney told the Times-News on Tuesday.

The attorney also called it “reckless, pure speculation” on the part of a sheriff’s investigator who said “many more victims” were likely to come forward.

Jansen was hired by TFPD in December 2013 and sworn-in March 2014 after completing training. According to his biography at that time, he was a sergeant in the Idaho Army National Guard and completed two combat deployments to Iraq.

A teenage girl came forward with the allegations two weeks ago and the police department turned the case over to the Twin Falls County Sheriff’s Office to investigate. County Prosecutor Grant Loebs also said he’ll refer the case to an outside prosecutor because it involves a local officer.

The girl who first reported Jansen last month said he sexually abused her in 2008 and 2009 when she was between 7 and 9 years old. Another girl contacted during the investigation said he abused her when she was 8, in 2005 and 2006.

“Based on my training and experience and the evidence gathered in this investigation, I believe more victims will be uncovered through the course of this investigation and Jansen remains a threat to society and any current/future victims,” Sheriff’s Detective Travis DeBie wrote in a sworn affidavit.

One of Jansen’s ex-wives also told investigators he confessed to inappropriately touching the girls and having sex with a 17-year-old girl.

The defense attorney questioned the ex-wife’s motive — “he left her when she was having affairs on him,” Scott told the court Monday — and called for heavy scrutiny of her claims.

“It seems unusual that if he made those (confessions) to her, and she was aware he had sex with a 17-year-old girl back in 2005 or 2006, that she takes until 2017 to bring it to somebody’s attention,” James said.

Jansen was also in another marriage with a woman who had three children, including two young girls “in the same age category as the alleged victims, and there is absolutely no indication he was involved in anything inappropriate with them,” James told the court.

James also told the Times-News his client was sent home early from his Mormon mission to the Philippines after confessing to a consensual sexual relationship he had before his mission with his future wife — the same one who accused him of abusing the young girls.

“I think the implication was far more nefarious than it is,” James said, adding Jansen did nothing inappropriate while on his mission.

Jansen is out of custody after posting $100,000 bond and is set for a preliminary hearing April 21.