WASHINGTON — A veteran Washington police officer and pastor has been charged with sexually assaulting two teenagers – one of them inside his church while he was wearing his gun and badge and the other inside the police headquarters building on Indiana Avenue NW, according to an arrest affidavit.

Darrell Lavon Best, 45, who lives in Upper Marlboro, Maryland, and has been on the police force for 25 years, was arrested Monday night in Largo, Maryland, by members of the Capital Area Regional Fugitive Task Force. He is pastor of God-A Second Chance Ministry Church in Southeast Washington, where both teens were members.

Best was charged with two counts of first-degree and two counts of second-degree sex abuse of a minor. He was detained pending a hearing set for Thursday.

A Washington police spokeswoman said Best, most recently assigned to the 4th District police station in Northwest Washington, has been put on administrative leave. Washington Police Chief Cathy Lanier said that the allegations are “serious and disheartening.”

“The fact that he used his position as a pastor and a counselor to gain access to his victims is extremely disturbing,” Lanier said. When Washington police “became aware of the allegations, we immediately conducted an investigation, obtained a warrant, and arrested him.”

Police said that a 16-year-old victim came forward to authorities Saturday and that an arrest warrant was sworn out Sunday. The other victim, who was 17 at the time, then emerged through the investigation, authorities said. Police said Best was off-duty at the time of the alleged incidents, though both victims told detectives that they knew the pastor was also a police officer.

Relatives of Best could not be reached Tuesday.

The phone number to the God-A Second Chance Ministry Church at Bowen Road and Southern Avenue SE was disconnected. The store-front church is along a commercial strip and is between a Dollar Plus and Food Market and a barbershop.

The arrest affidavit says that Best met the victim who was 17 at the time at the church and took her out on Dec. 4, picking her up in what she thought was a police vehicle. The affidavit says he took her to an expensive downtown restaurant and took off his green jacket to reveal a police uniform. He then took her into a building that she later identified as police headquarters, where he worked at the time and where she said he forced her to have sex on a couch under pictures of current and former police chiefs.

The arrest affidavit says that on Dec. 23, Best took the 16-year-old out in a black van and “into the local community to see the plight of young single women with small children.”

The girl told police that once they were back at the church, Best complimented her on her figure, and she said she repeatedly refused his overtures, according to the affidavit. Court papers say the victim said Best then forced her to have sex while he wore his police badge and belt with his gun, baton and handcuffs.

A second assault occurred either Jan. 15 or Jan. 17, police said, when Best allegedly took the 16-year-old girl out of choir practice. After, the affidavit says, the victim “returned to choir practice and told no one what occurred.”

The final incident, according to police, occurred Feb. 14, when the 16-year-old girl told detectives that the officer again took her out of choir practice and assaulted her in his office. The girl said in the affidavit that Best told her, “Happy Valentine’s Day.”