DENTON, Texas -- A family in Denton says their autistic ten-year-old son was injured at his elementary school by a police officer. They say a school resource officer used handcuffs on their child, and they have now pulled their son out of school.

Emily and Robert Brown say their son was diagnosed with a high-functioning form of autism.

"He is a bright kid, super smart," said mom, Emily Brown. "He has some social issues, where it's a little difficult for him to get along with other kids at school."

The Browns say their son attends Lee Elementary in Denton ISD. They recognize that their son needs special care to deal with some of his behavior problems, and they have what is called a Behavior Intervention Plan that spells out what the school should do if their son misbehaves. They said agreed-upon tactics include using a walk or cool-down room to help their son regain control.

"We never agreed for him to be mechanically restrained," said father Robert Brown.

But on April 30, Emily was called to school and found her son with a teacher, administrator and a school resource officer from Denton Police

"The officer proceeded to tell me that [my son] had been restrained in handcuffs twice before I had gotten there," said Emily.

She said she was not told about the restraints in advance, and she recalls the officer warning her about possible bruises to her son's head and arms. The officer said her child had been hitting his head against the floor. When they got home, though, she said they found bruising not just on his wrists but on his knees and back.

"We're talking about multiple marks on his knees that bruised. Deep bruises and knots," said Brown. "Something happened that was not told to me."

In a statement to WFAA, Denton PD said the school resource officer came to campus at the request of Lee Elementary staff to deal with a student who had been agitated all day.

"[The staffer] hoped an officer being present would help calm the student down," the statement said.

According to the statement, when the officer arrived, they found the student poking and pinching other students. The officer carried the uncooperative student out of the classroom, and the child kicked the officer, who handcuffed him and held him down to prevent him from harming himself.

The child "was not charged for assaulting the officer or school staff," the statement said.

The Browns say they asked questions about the specifics of what happened but received little information from the police department until WFAA's inquiry. After discovering the bruising to their son, they said they contacted CPS and filed a police report themselves.

"If I send my child to school that bruised and that beat up, somebody will call CPS on me," said Emily Brown.

For help navigating issues surrounding their son's disability, the Browns work with a firm called Advocacy Behavior Consulting.

Advocate Mike Holum says police style tactics are not the way to handle a ten-year-old autistic boy.

"With all the things that are happening in society today, I want police officers there [in schools] for health and safety," said Holum. "But I think we really have to look at things when that police officer is being used as discipline, specifically to a child with disabilities inside that school."