A year and a half ago, Maura opened her apartment door to find a stranger there, a man who said he was responding to an Internet classified ad inviting men to visit her for sex.

Immediately, she suspected Shawn Sayer, her ex-fiance, who had already served seven months in jail for stalking her. She went online and found the personal ad and saw the provocative image of her that Sayer had taken while they were engaged years before.

Later that night, while heading for the refuge of a friend’s apartment, she stepped into the pitch-black hallway and immediately felt someone’s presence behind her, then a hand caressing her back.

She shoved the man — not the same guy who showed up earlier — and he went toppling down the stairs before staggering out of the building clutching his injured nose.

Thus began a new and more sinister chapter in a four-year ordeal that followed her breakup with Sayer.

“It was devastating,” she said. “I went from being fearful of one man to pretty much all men.”

The episodes escalated to where, for the past few months, there would be two to six visitors responding to similar ads, almost every day of the week.

“It was scary day in and day out,” Maura said.

When she stopped answering the door, the men were instructed to knock on the window, or come to the backyard, or to her work, in each case believing the ads had been posted by her.

She posted signs in each window that read: “If you knock on my window, I will call the police” and “A man pretending to be a woman invited you here. Leave now.”

Maura, a 30-year-old resident of South Portland, offered to share her story to give strength to women enduring similar problems and to encourage police agencies to be more responsive when receiving such reports.

The Portland Press Herald is not using her full name to protect her privacy.

Despite the ordeal and her extensive efforts to adapt to it, Maura said her life was not ruined. She did not want to give Sayer that satisfaction.

Instead, she made coping with it just another of the labors in her busy life. She was going to nursing school and working two jobs.

She said she is blessed to have had supportive friends and neighbors.

Despite getting less than stellar help from a variety of police agencies over the four years, Maura declined to criticize specific departments, saying only that officers need to treat such reports seriously and improve their ability to respond.

“I don’t want to say I got no help. I would say it was subpar at best,” she said. “Had this been taken seriously in the beginning, it would not have gotten to this point.”

She is deeply grateful to the Maine State Police Computer Crimes Unit. A nine-month investigation by detectives led to Sayer’s arrest last week on charges of violating a protection-from-abuse order and violating bail conditions related to a previous charge of violating a protection order.

The case was challenging because, police say, Sayer was uploading images and fake ads using a laptop and publicly accessible wireless connections instead of his own Internet service provider. Tracing the source of the ads merely led back to the owner of the wireless Internet connection.

Police were able to assemble enough information to get a search warrant, but Sayer appeared to have been tipped off. Police found no laptop, and the hard drive from his desktop computer was missing.

A second search warrant last week led to the charges against Sayer.

Maura’s relationship with Sayer began in 2003.

Sayer has the ability to be very charming, as he was when they first dated, Maura said. He also was adept at emotionally isolating her, she said.

She had no idea he was capable of the pathological cruelty he displayed after they broke up in 2006.

“He’s just evil,” she said.

At first, he would show up at her house and her work, be at the grocery store when she was there, or the gym or at the beach. When she complained to police, he would turn on the charm and suggest she was crazy or exaggerating, she said.

“I’d be putting in a police report and he would somehow be able to schmooze them all,” she said.

Once she took his picture at one encounter, and he reported it as harassment. Police told her to stop.

Sayer was convicted of stalking Maura in 2007 and spent seven months in jail. After a brief respite, the behavior started up again, this time using the Internet, she said.

Exasperated, she took a dramatic step. She changed her name, left family and friends and moved to Louisiana, where a relative lived.

“I packed my car in the night. I left my curtains up so it wouldn’t look like I was leaving,” she said.

She was there two months when a man arrived at her door, looking for her by her new name, and said he was responding to a personal ad.

“I was devastated,” she said. “This was my chance to start over.”

Finally, she sent letters to the chief of the state police and to Attorney General Janet Mills, pleading for help for herself and other women facing similar situations.

“Please don’t let our mothers get that phone call every mother hopes she’ll never get,” she wrote to Mills. The letter found its way to the Computer Crimes Task Force, which began an investigation.

Maura still does not know how Sayer was able to track her movements.

“I have changed my phone number anywhere from a dozen to two dozen times,” she said. “It became just part of my life.”

One particularly unsettling development occurred when she signed up online to join a soccer league.

Within 30 minutes, she received a text message warning her not to get involved with the team.

Emily Flowers, a spokeswoman for Caring Unlimited, which serves domestic abuse victims in York County, said many high-tech gadgets and software intended for one use can be put to nefarious purposes by a controlling partner or ex-partner.

“We’re seeing it more and more often,” she said.

“What’s tricky about it is that it changes in an instant.”

In its annual report in January, the Maine Domestic Abuse Homicide Review Panel recommended launching a community awareness campaign about how modern technology, social networking sites and cell phones can become the tools of an abuser.

Advocates and police agencies are scrambling to keep up, learning how to scan a cell phone for spy gear or find tracking software on a computer, Flowers said.

Sayer, an occasionally employed carpenter, also had lots of free time to do research, police said.

Maura understands it’s easy for people to judge women in similar situations, and many feel shame, guilt and fear.

The abuse, whether physical or emotional, doesn’t start immediately, but builds gradually over time, she said.

“One day you wake up going, ‘How did I get in this situation and now how do I get out?’” she said.

Maura no longer uses e-mail or social networking sites. She communicates face-to-face or by phone.

She installed a four-camera security system and carries a mini-video recorder in case she is confronted.

Sayer is being held in the York County Jail pending an Aug. 13 hearing. Police say federal authorities are exploring additional charges.

Staff Writer David Hench can be contacted at 791-6327 or at:

[email protected]