Parents train their children from birth not to speak to strangers.

But according to counseling professionals, it’s the trusted friends – an uncle, a coach, a teacher, a religious leader – who are most frequently convicted of sexually abusing a child.

In fact, more than 90 percent of children who are molested know their abuser, according to the National Center for Prevention of Child Abuse.

“They don’t look like devils,” said Dr. Lawrence Ricci, director of the Spurwink Child Abuse Program, which has offices in Bangor and Portland.

“There’s no way to look at someone and know whether they’re going to sexually abuse a child,” he said recently. “It appears that sexual abuse crosses all socioeconomic lines.”

As many as one in four girls and one in 10 boys will be molested by age 18, according to the National Center for Prevention of Child Abuse. A 1996 federal survey estimated that more than 300,000 U.S. children are sexually abused each year.

The vast majority of these abusers are the parents, grandparents or siblings of their victims, said Ricci, who frequently works with the state Department of Human Services to investigate reports of child molestation.

“It is as true now as it has been in years past, that children are most likely to be abused in their own home,” Ricci said.

Little girls are particularly vulnerable to familial abuse, as surveys have shown that the vast majority of pedophiles are males, particularly those serving a “father figure” role.

But little boys are at a much higher risk of falling prey to the friendly predators who take them camping, coach their baseball team or lead their Sunday school class. U.S. society is protective of its daughters, but sometimes fails its sons, Ricci said.

Parents who would never send their daughters on a field trip alone with a grown man think nothing of sending their male children into the same potentially dangerous situation.

The best precaution a parent can take is healthy skepticism, guaranteeing that their child will never be alone with an adult whom they do not know well, regardless of that person’s title.

“Just because someone happens to be in a leadership role in the community doesn’t mean they’re a good person,” Ricci said.

These types of molesters are rare, but they can abuse tens or even hundreds of children before they are caught. Abusive relationships can continue for years.

“They are behaving – in all but this secret place – as pious, well-respected individuals,” Ricci said.

As a result, children who are abused by authority figures – particularly those who are molested by religious leaders – rarely report their abuse. The more authority an abuser has, the less likely a child is to report the crime. Only when they become adults do they feel able to reveal their secret.

Children will hint that something is not right, but the chances of a child actually telling his or her parents are slim, Ricci said.

“For many children who are sexually abused, the last person they are going to talk to is their parent,” he said. “If a child says anything about sexual abuse, [parents] need to take it seriously. They can’t ignore it.”

A third of abused children never show any signs, and other children exhibit the behavioral cues tied to sexual abuse in response to other, completely innocent stressors in their lives.

Children should never be asked to confront a potential abuser, Ricci said. Parents who fear that their child may have been abused should take a child to see a counselor or pediatrician, and report their suspicions to the Department of Human Services.

The Maine Bureau of Child and Family Services operates a toll-free, 24-hour hotline where child abuse and neglect may be reported, at (800) 452-1999.