Nevins was found dead in the rear seat of a scorching hot van about five hours after a small group returned July 24 to Woods Services, a residential treatment program in suburban Philadelphia. The temperatures that day reached 97 degrees.
Strauss had called a supervisor from a nearby amusement park that morning to say Nevins was causing problems, biting himself and trying to bite another client, the police affidavit states. She was told the group should return home. They returned to the Langhorne campus from Sesame Place at about 12:30 p.m.
Strauss, who was driving the van, told authorities she was only responsible for one client while the other counselor on the trip was responsible for the other three. But her supervisor told police she had assigned Strauss to watch Nevins and a second client.
Bucks County prosecutors expect Strauss will post her $50,000 bail by Wednesday.
"My son was essentially murdered by this woman," William Nevins, a retired New York City homicide detective who lives in Oceanside, N.Y., told The Associated Press. "Now we'll see what the people of Bucks County think the life of a disabled person is worth."
He described his son, a triplet, as severely autistic but said he enjoyed music, running, swimming and other simple things. He and a triplet brother had previously been well cared for in their five years at Woods Services, the father said.
"He could be troublesome at times," said William Nevins, 58. "But on the whole, he was very friendly, very loving, very outgoing."
Authorities said Bryan Nevins spoke only a few words, and had a care plan that required constant, arms-reach supervision on trips and within-sight supervision on the Woods campus.
Strauss, who lives with her 21-year-old son, had a good work record in eight years at the Woods Center, where she made about $11 an hour as a residential counselor, her lawyers said.
Defense lawyer Robert Lynch called her a "devoted public servant."
"There were many people working that day who were responsible, on many different levels," Lynch said. "Ms. Strauss did not put Bryan in that van, ... and was not assigned to him."
According to the police complaint, Strauss said she had seen all of the clients outside of the van when they returned, but conceded that she did not make sure Nevins was taken back to his building. She said she walked one client to his residence building after parking the van.
Nevins' absence in an adjacent residence went undiscovered until about 5 p.m., when a nurse sought to give him medications. He was long dead when his body was found in the rear seat of the locked van, the coroner said.
Bucks County District Attorney David Heckler called Nevins' death "a needless tragedy."
"Mr. Nevins' death was not simply a tragic accident," Heckler said in a statement. "Rather, his death resulted from the criminal failure of the defendant to discharge her assigned responsibilities to Mr. Nevins."
In another Bucks County case this year, a daycare owner charged with involuntary manslaughter for leaving a toddler in her vehicle was acquitted by a jury. Her lawyer said liability in such circumstances should be left to civil courts, instead of criminal prosecution.
"My sense of these cases ... is that no one deliberately allows a child or a handicapped individual to remain in a hot car," Michael Mustokoff said Tuesday. "Someone would have to be absolutely, morally numb not to feel the responsibility of causing a death."