Then there are Dr. Larry Nassar, Coach Jerry Sandusky and Father John Geoghan.

Society knows them as monsters.

Abuse in one of these vocations came to the fore of public consciousness just last week, when a grand jury detailed decades of allegations of child sex abuse by Catholic priests in Pennsylvania

Should parents question their assumptions, even about the kind of people often regarded as pillars of the community? That may sound cynical -- and to be clear, nobody suggests the majority of doctors, coaches and clergy have anything but the best motives -- but when it comes to leaving a child in someone's charge, experts say, there is no such thing as being too careful.

"Trust is overrated," said Marci Hamilton, a University of Pennsylvania fellow and CEO of Child USA, a think tank working to prevent child abuse. "Whenever there is potential for blind trust, it opens the door for the pedophile to get access to the child."

Hamilton suggests parents toss instincts and assumptions aside, difficult as it may be. Someone seeking to sexually abuse children first needs access, so working with youth-serving organizations can serve as a path to predation.

Parents also are inclined to grant leeway to the nice guy -- the teacher who showers praise on their kids, the youth group leader who shows Johnny extra attention -- when, in reality, being likable and charismatic is the modus operandi for those who prey on children, she said.

"That's the person to be worried about, and in the past it's the person we would've trusted the most," Hamilton said.

That's not to say friendly teachers or youth leaders are bad -- quite the opposite -- but opting for vigilance over assumptions can go a long way to keeping kids safe.

"Our society has to find a balance between denial and paranoia," said Kenneth Lanning, who spent 30 years with the FBI, 20 of them with what is now known as the Behavioral Analysis Unit.

Lanning, now a consultant on crimes against children, refers to abuse by teachers, doctors and the like as "acquaintance molestation," and statistics say your child is most likely to be abused by someone they know. Stranger danger -- the predator hiding behind the schoolyard tree offering kids candy -- is a threat, especially to little ones, he said, but it's not as common as acquaintance molestation.

Here's what parents should keep in mind:

Accept it happens -- too often

According to Darkness to Light, a nonprofit combating child sex abuse, one in five adults report being sexually abused as a child. Broken down, that's one in four women and one in six men, according to a 2013 Darkness to Light white paper

That's an average of four or five youngsters in a typical American classroom, or about four players on an average youth soccer team.

More than nine out of 10 victims know their abuser, according to the Rape, Abuse & Incest National Network . While about a third of perpetrators are family, almost 60% are acquaintances, RAINN says.

"There are people in power who place themselves there in order to hurt children, and that's a scary thing to admit to oneself," said Darkness to Light president and CEO Katelyn Brewer. "We love these institutions. Part of what is so painful is we don't want an institution we love to be involved in such a horrific crime."

Reported is a key term, as Darkness to Light cites figures estimating that only 38% of child victims report sex abuse

Open dialogue

Talk to your kids early and often, and not in a one-off, birds-and-bees sort of way, Lanning said. It can be uncomfortable, but get over it. The conversation sounds different for a 4- and for a 16-year-old, or for boys as opposed to girls, so keep that in mind, he said.

With 4-year-olds, parents may want to focus more on stranger danger and relatives, while remaining aware that the child will have comprehension issues when it comes to understanding what is inappropriate. With teens, moms and dads need to focus more on acquaintance molestation, while taking into consideration youngsters at that rebellious age may be less likely to heed parental warnings.

Jaquelyn, a Cobb County, Georgia, mother who believes her son was sexually abused by his wrestling coach, wishes now she would have known how to talk to the boy when the man was taking special interest in him.

She said she did sometimes ask her son questions about his closeness to the coach, but "I questioned my son in a way that probably made (him) feel defensive."

"I would say, what's going on? Did he do this and did he do that? ... Had I allowed him to speak instead of just drilling him," maybe he would have felt comfortable saying something, said Jaquelyn, who didn't want her last name used because it would identify her son.

Talks with children can be further complicated by parents' belief systems regarding matters such as homosexuality or premarital sex, so Lanning says parents must find ways to talk with their kids "in the context of your religious beliefs and your morality."

Don't shy away from precise language, Lanning added. Too often, parents rely on euphemisms -- "making sandwiches" or "bumping uglies" -- but terminology is essential to understanding the nature of abuse, especially when reporting it to authorities, he said.

Ultimately, the goal is to get a child comfortable talking to her or his parents. Opening up avenues of communication early can spur your child to report a crime after the first incident, rather than after the 50th.

Do homework

Lanning is wary of putting too much of the onus on parents, though he and other experts concur they're the last line of defense. According to Lanning, parents are typically not professionals, they're emotionally entangled and they're rarely objective when it comes to their kids. Still, he'd like to see parents thoroughly research organizations they're trusting with their children.

The groups themselves should intensely screen both staff and volunteers, supervise employees and manage their interactions with children, have an established response to abuse allegations and actively practice prevention and awareness, Lanning said.

Parents need to make sure the institution has what's called a "two-deep policy," Hamilton added.

If a pediatrician is treating your child, a nurse or parent needs to be present. Teachers should leave doors open when they speak to children one-on-one, and if the conversation requires privacy, another teacher needs to be in the room. Coaches should never be alone with kids in locker rooms, especially when they're showering. In the case of Catholics, Hamilton suggests parents accompany their kids into confession, even if it hampers what they're willing to confess.

Every organization charged with a child's care should, in policy and practice, allow parents to observe their kids at will, experts say. Period. No exceptions.

Watch for red flags

"Part of what pedophiles do is not only groom kids, but groom the adults in kids' lives," said Teresa Huizar, executive director of the National Children's Alliance.

Kids should be taught what to look out for, but parents need to be cognizant that someone seeking to abuse children will seek to lower the parents' inhibitions as well. While it's good for children to be suspicious when a slap on the back becomes an arm around the shoulder then a pat on the butt, parents, too, should be wary of any progressive attempts to get a child alone.

In both cases, the abuser will work gradually to lower the child's and parents' guards.

"They don't want to scare your child. They want to form a relationship," Huizar said. "That pattern of progression is something I think people need to be able to spot and identify."

Jaquelyn said her son's wrestling coach offered the boy rides home, invited him to his house, took him out to dinner and sent gifts. The coach was later convicted of sexually assaulting two boys in Pennsylvania , where he lived before moving to Georgia.

"Beware of anybody who wants to be with your kid more than you do," Lanning said.

Forget stigmas

Parents too often worry about briefly offending daycare operators or teachers, when they should be more worried that a sexually abused child can face a lifetime of traumatization, Huizar said.

Jaquelyn advises parents to question everyone who wants to be involved with their children, and their motives.

"Anyone who takes an extra interest in any kids who aren't their own" should be looked at carefully.

It's OK to press about whether a school, church or daycare has had issues with abuse in the past, and if they have, what they did about it. Parents should ask if all offices have glass doors and if children are visibly observable at all times, Huizar says. Don't worry about being impolite.

The reality is this: People with a child's best interest in mind have no issue answering questions. They won't be offended. They won't be defensive. If they are, parents are right to be suspicious.

"That's an enormous red flag in and of itself," Huizar said.

Listen, listen, listen

In the relatively rare instance that a child does come forward with allegations of sexual abuse, it's imperative parents listen. Their first reactions should never be to question the account, experts say. Responses such as "Oh, c'mon, not Uncle Joe," or "But I thought Coach Johnson was your favorite," can spark doubt in a youngster's mind, prompting them to recant.

Kyle Stephens, a victim of former Team USA doctor and family friend Larry Nassar, told her parents at age 12 that Nassar was abusing her. They didn't believe her.

Asking too many questions as a parent can also result in inconsistencies in a child's recollection, which can be problematic when reporting it to police and when prosecuting the abuser, said Darkness to Light's Brewer. She urged parents, upon learning of abuse, to immediately contact authorities so that an expert can examine the child and take her or his statement.

It's also important to understand that while children rarely lie about being sexually abused, they may provide inaccurate details, experts say. If the child is younger, that could be due to lack of understanding. With older kids, they may feel guilty.

Did they let the priest rub their back in hopes of currying favor? Did they overlook the touching because the coach promised a scholarship or gold medal? Did they drink alcohol or smoke pot or watch pornography with the person who abused them?

None of this is important because, no matter the child's actions, they can't consent to sexual activity, Brewer said.

"The things that you demand that they don't interact with are ways that these perpetrators are contacting them and enticing (your children) to spend time with them," she said. "Getting angry at the child is only going to increase the shame."