How Adults Can 'Groom' Vulnerable Children: What Parents Need to Know in Wake of Missing Teen's Alleged Abduction

In the months leading up to the disappearance of Elizabeth Thomas, the 15-year-old was allegedly “groomed” by the man authorities believe abducted her: her 50-year-old teacher, Tad Cummins.

But nobody saw any signs.

“That to me is terrifying,” her brother, 27-year-old James Thomas, has told PEOPLE. “[That] he had that much control over her without anyone knowing.”

Now, as the search for Thomas continues since she went missing March 13, alleged details about her and Cummins continue to emerge. Cummins was allegedly caught kissing Thomas in January at the Culleoka Unit School, where he was a teacher and she was a student. The pair allegedly wrote what authorities described as “romantic” emails to each other and went to church on Sundays together.

However, authorities have cautioned that the alleged relationship between the two was a manipulation - and not a “romance.”

“Some have characterized this relationship as a romance. But this morning I want to caution the public to avoid anything that might look or sound like victim blaming,” Mark Gwyn, the director of the Tennessee Bureau of Investigation, told reporters on Tuesday.

While investigators put the pieces together, one expert tells PEOPLE the allegations against Cummins illustrate warning signs about potential predators for parents and schools.

Exploiting Vulnerabilities

Like most teenagers, Thomas had her insecurities and weaknesses. The high school freshman grew up homeschooled, and in 2015, her mother lost custody of her and her nine siblings for alleged child abuse and neglect.

(Kimberly Thomas faces child abuse and neglect charges and will appear in court May 12, Cooper tells PEOPLE. She has denied the charges in published reports but has not yet entered a plea. It was not immediately clear if she has retained an attorney.)

Former FBI agent Ken Lanning, who specialized for more than two decades in crimes against children before retiring in 2002, tells PEOPLE that most abusers look for vulnerabilities they can exploit in their victims.

“What are her needs, wants and desires?” Lanning says predators ask themselves. “You have to customize your grooming to the child. So you decide what needs this child has, you move in and fill those needs.”

In January, Cummins was allegedly caught kissing Thomas in his classroom. Cummins also allegedly told a student he was a “father figure” to Thomas and was trying to help her with issues at home.

“He obviously used those angles to work on her,” Jason Whatley, the Thomas family’s attorney, alleged to PEOPLE. “It’s horrific.”

A warrant has been issued for Cummins’ arrest on charges of aggravated kidnapping and sexual contact with a minor.

Paying Extra Attention to a Child

Lanning, who was assigned to the FBI’s behavior science unit before he retired in 2002, says parents should be wary of anyone who pays more attention to their child than they themselves do.

“Does this adult, who has an interest in your child, do they seem too good to be true?” Lanning says. “The reason so many guys get away with this is because people tend to believe what they want - that the teacher (or person) is paying special attention to their child to help them.

“So you suddenly begin to see this guy in a [positive] light,” he continues.

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Thomas’ older sister, Sarah Thomas, previously told PEOPLE that her sister spent time between classes in Cummins’ classroom. Anthony Thomas, Sarah’s father, says his daughter was being bullied, which Lanning says Cummins could have also used in his favor.

Cummins has been described by colleagues and officials as a “well-liked” teacher at the school. Lanning says being well-liked could be part of a predator’s plan.

“He’s [not only grooming her] but grooming other people, including his supervisors, convincing her parents that he’s a nice guy and a good teacher and therefore he gets [more] access to her and once he gets access to her he gets control of her,” Lanning says.

Special Privileges

Another part of the “grooming” process is creating a positive relationship through special privileges, Lanning says.

In a previous interview with PEOPLE, Thomas’ family said the 15-year-old would hang out in his classroom because he had a microwave for her to heat her food in at lunch and a cot for her to take naps on. Cummins called Thomas his assistant, her family says.

“He built up a system where she was dependent on him,” Anthony Thomas said.

Speaking generally of improper situations in which teachers prey on students, Lanning says, “This didn’t happen one afternoon at school.”

He adds, “And not only does she not tell anybody about it but the next day she goes back.”

A week after Cummins was reported for the alleged kiss in January, Thomas’ family was contacted by authorities. When her family spoke to Thomas, she denied the kiss took place and said she was excited to see Cummins again in school.

Speaking about the moment he found out about the alleged kiss from the Maury County Sheriff’s Office, Anthony Thomas told PEOPLE, “I was in shock.”

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The Tennessee Bureau of Investigation asks anyone who believes they may have seen Cummins or Thomas to not approach them and instead keep an eye on them while calling 911.

Thomas was last seen wearing a flannel shirt and black leggings. She is 5 feet 5 inches inches tall and weighs 120 lbs., with blonde hair and hazel eyes.

Cummins was seen driving a Silver Nissan Rogue with Tennessee license plate 976ZPT, according to the TBI. He is 6 feet tall and weighs 200 lbs., with brown hair and eyes.

Anyone with information on Cummins or Thomas should call the TBI at 1-800-TBI-FIND.

This article was originally published on PEOPLE.com