ATLANTA, Georgia (CNN) -- It's happened again. A teacher is accused of having sex with a student and, like many times before, cell phone calls and texting reportedly had a role in sexually abusing a minor.
The same cell phones that parents buy as safety devices for their children are the gadgets that pedophiles and predators use to prep kids for sexual encounters, experts and police say.
The latest case is out of Pennsylvania. Police say a 26-year-old P.E. teacher admitted to having sex with a 14-year-old student in the school's parking lot.
Detectives from the Moon Township Police Department said they found nude pictures of Beth Ann Chester on the teen's cell phone along with text messages.
Chester faces 14 charges, including three counts of sexual abuse of a child and involuntary deviate sexual intercourse. Watch police describe how Chester explained the relationship »
Robert Del Greco, Chester's attorney, declined CNN's request for a comment. His client has a preliminary hearing on January 22.
Before cell phones, laptops and Sidekicks -- a BlackBerry-like device for the younger, hipper crowd -- someone might have noticed that a teacher was "grooming" a child, or being way too attentive, too often.
Now, teachers have weeks, months and years to secretly undermine a child's parents and get a student to go along with sexual contact.
"The fact is a teacher can show absolutely zero outward signs of interest in a child, but because of technology, they can have an ongoing relationship and no one would know," said Ted Thompson, the executive director for the National Association to Prevent Sexual Abuse of Children.
Parents know chat rooms are dangerous. They warn their kids about the risk, but they give cell phones a nod.
A New York mom, who requested anonymity because her kids don't know about her surveillance, said she uses software to regularly check her children's e-mail and online activity on the home computer.
But she also gave her kids cell phones that have texting and photographic capability. Asked why she doesn't scrutinize the phone the same way she snoops on the computer, she said. "I hadn't really thought about it much."
Detective Joshua Shelton, who works in the crimes against women and children's unit in Fayette County, Georgia, says most parents are like that. He's investigating a case in which a teacher allegedly sent a message to a 14-year-old student's cell phone requesting a nude picture of her.
"Parents don't have the involvement that they should with these electronic devices," Shelton said. "Parents should consider cell phones that have Internet access like a window open into their house, because that's exactly what these people are using it as."
Start platonic, get physical
Betsy Ramsey has spent 20 years working with child and female victims and chairs the DeKalb County Domestic Violence Task Force in Georgia. Stalking of adults and grooming of kids almost always involve using electronic devices these days, she said.
"This is the way people communicate today, particularly young people," she said, "and sometimes, you have teachers who are not that much older, because they are just starting out, and they grew up with text messaging."
Often adults who have their eyes on a child invest time in making them comfortable, police said.
"They groom children," Shelton said. "A lot of the time, these kids mistake the grooming activity for friendship, which is exactly what it's designed to do -- to look like a platonic relationship, when all they are really doing is getting closer and closer to them socially so they can get closer and closer to them physically."
A recent case involves Kelsey Peterson, a 25-year-old Nebraska teacher accused of having sex with a 13-year-old former student. She faces federal charges for allegedly kidnapping the teen and taking him to Mexico to have sex.
An Associated Press reporter, Elliott Spagat, interviewed the boy while he was in Mexico and told CNN about it. The boy recounted being groomed, telling Spagat that Peterson "was his best friend. He was having problems with gangs ... and he said she would lend an ear whenever he needed it," Spagat said. Watch for the boy's side of how the relationship started »
Peterson's lawyer, James Martin Davis, said that's not what happened and there was no grooming or pursuit by his client.
Peterson has pleaded not guilty to the federal charges, but Davis said, "I would plead her guilty to what she did, which was statutory rape, if they proved his age to me, but they haven't got a certified birth certificate." Davis says the boy and his family were here illegally and had numerous fake documents.
Davis says his client is not a "dirty old woman," and that the victim told him he was older and already had children. "The thing about these teacher-student cases is that these boys are not children. They are teenage males. There is no one more sexually aware than these teenage males," Davis said.
"I'm not saying it's right. It is a crime," Davis said. "But we are not dealing with children. I have 14- and 15-year-olds that are tried as adults when they are defendants, but we want to baby-fy them when it comes to these kinds of cases."
Peterson also faces charges in Lexington, Nebraska. The Lexington complaint against Peterson accuses her of child abuse, kidnapping, delinquency of a minor and two counts of sexual assault of a minor.
She has not been arraigned on the Lexington charges to enter a plea because authorities are working out which case to pursue, Davis said. "They are not going to double try her."
Love letters and vodka
One teacher spent four years building a friendship with a student, authorities said. Troy Mansfield was the third-grade teacher of the little victim with the blond ponytail, said Trooper Robert Norton, of the Pennsylvania State Police.
Mansfield sent her poems via e-mail, and the girl said she felt like she could confide in him. By the time she was in seventh grade, they were comfortable talking about sexual fantasies, and he'd sneak her away from school in his car for an hour of sex, Norton said.
Norton recalled that the child was a few minutes into testifying, when Mansfield needed a recess. "We arranged the e-mails in chronological order. She was on the stand reading hers, and I would read what he wrote to her," Norton said.
"We were about five or six e-mails into it, and his lawyer said that his client needed a recess, that he didn't feel well. He stepped outside of the courtroom, and just outside of the courtroom Troy Mansfield fainted. He pleaded guilty the next day."
Mansfield is serving up to 31 years in jail.
The wooing via text messages, cell phone calls and e-mail is so subtle, so affirming and so indulgent, that by the time a teacher makes inquiries involving nudity, a child probably isn't alarmed, Ramsey said.
"They will be supportive of behavior that the parent would not be supportive of, and the child gets an opportunity to do things that they cannot do at home," Ramsey said. "That is like a teenage dream."
A 14-year-old boy who had sex with 26-year-old Kelly Dalecki of Florida told police as much. Dalecki was a teacher at the same school where his mother taught, and she socialized with his parents.
According to police investigation notes, when the boy was 13, Dalecki gave him her cell phone number and an alias e-mail address. She bought and gave him Mike's Hard Lemonade, cranberry juice with vodka, condoms and marijuana, the documents state.
By the time she started e-mailing porn and illicit messages, he trusted her. "She would ask me if I was a virgin," the boy is quoted by police as saying. And she starting asking him about his interest in knowing about oral sex, police notes state.
The 14-year-old described what happened to him as consensual sexual intercourse, told cops he started to think, "How cool it was a woman her age wants me," and that, "Around me, she tried to act like a teenager, but around my parents, she acted like an adult," his statement to police reads.
Dalecki pleaded no contest to lewd and lascivious battery and was sentenced to 364 days in jail.
Thompson, of the National Association to Prevent Sexual Abuse of Children, said that if parents hope to protect their children, they cannot limit discussions to cover only invasive acts.
"If you think your kids are protected because they know that if they are touched in their private areas or if somebody undresses in front of them or attempts to perform a sexual act that that is the only bad thing, then they are not going to be prepared for the subtle, the grooming piece," Thompson said.
And there's something else Thompson recommends. Limit a cell phone's abilities. Allow it to make and accept calls to and from parents and 911 only.
"I know the societal pressure is for parents to get their kids the latest phone with all the gadgets that are out there," Thompson said, "but more important than complying with all the societal pressures is protecting your child." E-mail to a friend