SIERRA VISTA, Ariz. - A special agent with the U.S. Border Patrol was taken into custody Thursday for sexual conduct with a minor and sexual assault following a standoff at a church just outside of Sierra Vista.

According to officials, Sierra Vista Police Department and Homeland Security were investigating 49-year-old Dana Thornhill in connection to multiple ongoing incidents of sexual abuse involving children.

Police said while investigators were surveilling Thornhill, he allegedly fled Sierra Vista and entered a church located in the 2500 block of North Calle Segundo in Whetstone. SVPD said the Border Patrol agent gave the detectives an impression that he was armed with a semiautomatic pistol and was aware that law enforcement officers were attempting to arrest him.

Police said Thornhill reportedly then barricaded himself into the church.

A SVPD tactical unit was dispatched to the scene.

After four hours and a successful negotiation, Thronhill was arrested at around 8 p.m. that evening.

Thornhill was booked into Cochise County Jail on two counts each of sexual conduct with a minor and sexual assault. He is being held without bond, according to SVPD.

News 4 Tucson reached out to U.S. Customs and Border Protection in order to provide the following statement about Thornhill's arrest.

A Tucson Sector Border Patrol Agent was arrested Thursday evening by the Sierra Vista Police Department for sexual conduct with a minor and sexual assault, and booked into Cochise County jail. CBP stresses honor and integrity in every aspect of our mission, and the overwhelming majority of CBP employees and officers perform their duties with honor and distinction, working tirelessly every day to keep our country safe. We take all allegations of employee misconduct seriously and strive to be as transparent as possible regarding the release of investigative information to the public. CBP does not tolerate corruption or abuse within our ranks, and we cooperate fully with all criminal or administrative investigations of alleged misconduct by any of our personnel, whether it occurs on or off duty. CBP’s Office of Professional Responsibility is cooperating with the investigation into the alleged unlawful conduct and further inquiries should be directed to the Sierra Vista Police Department. U.S. Customs and Border Protection

The investigation is on-going.

Anyone with information about the case is advised to call 520-452-7500.