Aug. 23, 2013 -- Emma Saylor got a frantic call from her mother last January that her 26-year-old brother Ethan had been rushed to the hospital after a confrontation with Frederick County, Md., off-duty sheriff's officers at a movie theater showing of "Zero Dark Thirty."
Ethan, who had Down syndrome, enjoyed the film so much that he decided to go back to his seat for a second showing while his aide went to get the car to take them home. When he refused to buy another $12 ticket, off-duty police moonlighting as security guards allegedly tackled him in an attempt to eject him from his seat.
An hour later, the young man was dead from "asphyxiation by homicide," according to the medical examiner's report.
The case went to a grand jury, which declined to indict the three sheriff's officers involved in the Jan. 12 incident, according to the Washington Post.
And now Saylor, 23, wants some answers about what happened to her older brother. "It was unreal," said Saylor, who works in affiliate relations for the National Down Syndrome Society.
"It's not clear what happened exactly and that's where our questions are coming from," she said. "All we know is he ended up dead. No one expects their brother to go to a movie and not come home."
Saylor said when the mall officers pulled Ethan from his seat he panicked and then screamed for his mother.
When the aide, whom Saylor would not identify, returned to witness the police asking Ethan to buy a ticket or leave, she told them he didn't like to be touched and would "freak out." The family alleges officers ignored her pleas as Ethan was handcuffed and dropped to the floor, then stopped breathing.
Saylor said the aide was "too upset" to make much sense of what was happening.
When ABCNews.com asked Sheriff Chuck Jenkins for the police report on the incident, which was made public in July, he referred all requests to the agency's lawyer, Daniel Karp. However, Karp was in court at press time and could not return calls for comment.
Now, Saylor has filed a petition on change.org calling for a new investigation and better law enforcement training, which has garnered more than 207,000 signatures. She has also asked the Maryland attorney general and governor to reopen the case.
The National Down Syndrome Society has asked the Justice Department to investigate whether Ethan's rights were violated under the Americans With Disabilities Act. A Department of Justice spokesperson would only confirm that they are "reviewing" the case.
Saylor says her brother, at 5-foot-6 and 294 pounds, was "overweight" and the Chief Medical Examiner Office in Baltimore indicated that may have contributed to the asphyxiation. The medical examiner also noted damage to Ethan's larynx that may have contributed to his death, according to numerous press reports.
"The manner of death was determined to be homicide," said Bruce Goldfarb, assistant to the chief ME. "It was complicated by Down syndrome, atherosclerotic disease and some cardiac abnormalities."
After living independently in an apartment, Ethan had decided to return to live in an in-law apartment at his family's home in Frederick with his parents, sister and 21-year-old brother Adam.
Saylor said her brother had a sunny disposition.
"He was always making us laugh and doing something goofy," she said. "Often we would drive to the mountains and do something special together. He was very funny and could lighten any mood in any situation."
Police indicated that Ethan had been belligerent, according to reports in the Washington Post. But Saylor said that was not typical of adults with Down syndrome or her brother.
"I would not call it an aggressive side," she said. "When it came to communication, he had a lot of frustrations. He had language skills, but when he was overwhelmed or over-stimulated, they kind of went out the window. That's why he had staff with him and why she tried to advocate for him and tell the officer what Ethan needed."
Cpl. Jennifer Bailey, a spokeswoman for the sheriff's office, told the Washington Post that Ethan swore and began kicking and hitting the deputies, who were not in uniform.
She said the officers held him down with three sets of handcuffs linked together and removed him from the theater. Ethan landed on the ground and showed signs of medical distress and was transported to the hospital, where he died.
Calls to Bailey at the Frederick County Sheriff's Office were not returned. Reports in the Washington Post indicate that a grand jury declined to bring charges and the three deputies are back on the job.
ABCNews.com called the Maryland Attorney General's office for comment, but they did not return calls.
Saylor said that the police report had numerous statements from witnesses: "Some said that the deputies had their hands on his shoulders and knees and back; and others said they went down on a pile on him. That's why we want it investigated -- there is no explanation in the report how he suffered these fatal injuries."
She said the grand jury concluded that Down syndrome was the cause of death, but, said Saylor, "that's a condition like having an extra finger."
Down syndrome occurs when an individual has a full or extra copy of chromosome 21. One in every 691 babies in the United States is born with the condition, making it the most common chromosomal condition, affecting about 400,000 Americans, according to the National Down Syndrome Society.
"People with Down syndrome as just like everyone else," said Sarah Weir, vice president of advocacy for NDSS. "Some people don't mind people in their personal space and others have a problem with it."
"A lot of what happened with Ethan and the three officers is ignorance," said Sarah Weir, vice president of advocacy for NDSS. "Ethan has a right to be in the movie theater and a right to live independently in his community. He could have been graciously removed from the theater: 'Ethan, want to go get some popcorn' rather than forcing him to the side on the ramp and forcing him down to the ground."
"It's obvious the officers had been poorly trained and if they had been patient, they could have handled the situation completely differently," she said.
Now, Saylor said she feels an obligation to the brother who was so good to her.
"We just want to find the truth," she said. "We want to know what happened through the investigation. There are lots of gaps and holes. This is my brother and this is my family. I am not doing my job as his sister if I don't find out what happened."
ABC News' Mike Levin contributed to this story.