Ellen Murray cheats at games. She swindles, hoodwinks and tricks the kids she is playing with. And then she has to explain to them what just happened.

“They will always let me take their turn, again and again,” said Murray. “And we have to teach them to stand up for themselves.”

Murray is a clinical manager at the Center for Autism and Related Disorders in Alexandria. She works with children who have been diagnosed with autism, and the number one concern that parents want her to address is that their vulnerable, trusting children will be taken advantage of.

“That’s the biggest fear — the bullying,” she said.

So imagine how alarming it is for those parents to hear about the case of an autistic boy at Chopticon High School in Southern Maryland who was allegedly bullied and assaulted by two teenage girls. Among the alleged incidents recorded on a cellphone: a knife being held to the 16-year-old’s throat, his repeated falls through an icy pond after he was encouraged to fetch a basketball and his efforts to have sex with his family’s dog at the behest of two girls he considers his friends. In fact, the boy told The Washington Post’s Ian Shapira that he forgives the girls, wants the charges dropped and doesn’t think they meant any harm.

One of the girls, who is 15, pleaded guilty to second-degree assault and was sentenced Thursday to a juvenile lockdown facility for a maximum of six years. The other girl, 17-year-old Lauren A. Bush, has been charged as an adult with first-degree assault, child-pornography solicitation and false imprisonment and, if convicted, faces up to 80 years in prison.

And here’s the worst part: The girls may have preyed on two other students, the St. Mary’s County prosecutor told the judge Thursday. At least one of them was physically disabled.

Diagnoses of autism are soaring. In 1985, one out of 2,500 Americans were diagnosed with the disorder, which impairs social interactions and the ability to communicate. Today, one in 68 Americans are being diagnosed. And children with the disorder are being included in mainstream classrooms at higher rates every year. In 2000, there were about 94,000 children with autism enrolled in public schools. In 2011, that figure rose to about 417,000, according to the U.S Department of Education.

Studies have shown that a mainstream education — with the assistance of aides or a mix of specialized classes — helps children with autism thrive.

“Everything has shown us that kids with disabilities do better on all outcomes when they are integrated,” said Maureen Fitzgerald, the director for disability policy at The Arc, a national advocacy group for the developmentally disabled.

And let’s be real. The benefits are twofold, because when we raise children who have grown up around those who are different, we get better humans, Fitzgerald said.

But inclusion — or mainstreaming — is fraught with challenges. Sometimes parents of kids with no disabilities complain about the time being devoted to special-needs students. I also hear horror stories from parents trying to get proper assistance for their kids with special needs.

The parents of young kids worry they will bolt or harm themselves. For them, the nightmare scenario is Michael Kingsbury, the Washington 7-year-old who wandered from his home last summer and was found dead 32 hours later in a sweltering, abandoned car just 40 feet from his house.

But when kids with these developmental disabilities get older, the anxieties often become different, and darker. Parents worry about what others may do to them. And the heinous allegations in the St. Mary’s case fuel their fears.

One night this week, in an office park in Alexandria, the cupcakes and cookies far outnumbered the three officers who appeared after work for a training session on autism at the center where Murray — the game cheater — works.

All three were hungry for help on how to address the autistic children they encounter in the Northern Virginia schools they patrol. The officers said they are looking for ways to recognize autistic kids so they know how to respond to them and the situations in which they may be being bullied or targeted.

The staff at the Center for Autism gave a presentation to show officers what the typical signs of autism could be.

“You may see rocking back and forth, the flapping of arms and no direct eye contact,” said Michael Miller, the supervisor at the center. “They might not recognize the uniform, they may not understand rules or laws.”

“Can you come to our roll call with this?” one officer asked.

Staff, teachers and students all need this. Especially when it comes to the social jungle that teenhood is.

“It has to become part of the curriculum, the social part,” said Mary Ann Cassell, the senior managing supervisor at the center in Alexandria.

Many kids with autism have a hard time in social situations, and they are very trusting. They are the ideal targets for bullies, something that a 2012 study published in the Archives of Pediatric & Adolescent Medicine showed when half the kids researchers watched were harassed. Autistic children are four times as likely be to targeted as kids without developmental disabilities.

Leigh Ann Davis has studied this since 1994 and has seen some horrific cases of bullying and physical, sexual and emotional abuse of kids with disabilities. But she’s relieved to see parents are starting to come to her to help deal with bullies and assert their children’s rights.

“It can become a hate crime issue when people with disabilities are treated differently, are less valued and are taken advantage of,” Davis said.

“In my opinion, they did me a favor,” the St. Mary’s boy told The Post, referring to the two girls arrested in his case. “They helped me toughen up.”

Better to “toughen” them up with Murray at the Center for Autism, where children who are vulnerable and trusting go to school to learn about deception and lying.

It’s survival, but it’s also a little sad.

Twitter: @petulad

To read previous columns, go to washingtonpost.com/dvorak.