A father and son both were summoned Thursday on a charge of sex trafficking after Maine State Police say they uncovered a prostitution operation centered at their house in Sidney.

Frederick Horne Sr., 46, and Frederick Horne Jr., 19, both of 2874 West River Road, were issued summonses after police officers descended on the house Thursday afternoon, the culmination of what authorities said was a two-year investigation.

A mobile home in Litchfield was also targeted by police Thursday, and Gretchen Patrick, 51, of Augusta, was charged with sex trafficking in a separate, unrelated prostitution business, according to Steve McCausland, spokesman for Maine Department of Public Safety.

In Sidney, the Hornes were each charged with sex trafficking, a class D crime, according to Kennebec County District Attorney Maeghan Maloney, who accompanied state troopers and agents with the Maine Drug Enforcement Agency at the Sidney home Thursday.

Maloney estimated that at least a half-dozen women were at the home — site of Adam & Eve escort service, according to police — all of whom were interviewed by police. The women were not arrested, she said.

“The focus of the investigation is on those promoting the prostitution and those engaged in sex trafficking,” Maloney said. “The focus is not on the women at this time.

“This is not a victimless crime,” Maloney added.

Horne Sr. told the Morning Sentinel on Thursday that he was renting out rooms in his home to women.

Maloney accompanied the Maine State Police and Augusta police along with the Federal Bureau of Investigation, the Computer Crimes Task Force and Maine Drug Enforcement Agency while executing the warrant mid morning.

In Litchfield, Patrick, was charged with sex trafficking after police said she was running an escort service called Sarah’s Place from a mobile home in Litchfield. The residence was raided mid-afternoon, and police said the operations were not related.

Maloney said the investigation into the prostitution has lasted about two years and involved surveillance, phone calls and “conversations with women who have worked for them.”

Horne was arrested previously in 2006 on a charge of possession of a schedule Z drug after police pulled him over with a bottle of pills in his car. During that time, Horne owned an erotic rubdown parlor called Gentleman’s Choice on Main Street in Waterville, according to Morning Sentinel archives. In October 2005, two women working at Horne’s parlor were charged with engaging in prostitution after meeting with undercover officers.

Several advertisements for both escort services have been published on the classified ad website backpage.com and in Morning Sentinel classifieds section, under “ADAM & EVE: Adult Entertainment,In/out calls. Now Hiring!” and “SARAH’S: Adult Entertainment, In/Out calls.”

The bust came the same day that Gov. Paul LePage signed a bill that helps keep human trafficking victims from facing criminal conviction. The new law makes sex trafficking an affirmative defense to the charge of prostitution, preventing victims of trafficking from being branded with a criminal conviction.

The measure also fines perpetrators of sex trafficking $500 to $1,000 in addition to existing penalties and allows victims to draw from the Victims’ Compensation Fund. The bill, L.D. 1730, proposed by Rep. Amy Volk, R-Scarborough, has support from several organizations that prevent sexual violence, including the Maine Coalition to End Domestic Violence and the Maine Coalition Against Sexual Assault.

“Human trafficking is a horrific crime and I congratulate Rep. Volk for her tireless efforts to pass this legislation,” LePage said in a news release about signing the bill. “It’s important we protect those who cannot protect themselves and if the defendant was herself a sex trafficking victim this bill seeks to address that.”

The National Human Trafficking Resource Hotline, a phone line for everything from crises to general information, saw calls from Maine double in recent years, from 22 in 2009 to 44 in 2012, according to a 2013 story by the Portland Press Herald. During the same period, the hotline saw its national call volume go from more than 7,600 to nearly 21,000.

Jesse Scardina — 861-9239[email protected]Twitter: @jessescardina