DALLAS (CBSDFW.COM) – The principal at Hillcrest High School in Dallas says he feels “betrayed” by the 25-year-old man who posed as a 17-year-old basketball player.

“It’s a painful thing for us to process,” said principal Chris Bayer. “There’s kind of like a grieving process for us. We’re still kind of in the shock phase.”

Sidney Gilstrap-Portley posed as 17-year-old Rashun Richardson to enroll at Hillcrest in November of last year.

Sidney Gilstrap-Portley (Dallas County Sheriff’s Office)

He lied to the district about being displaced by Hurricane Harvey and exploited a loosened district policy for disaster victims.

“And to abuse that is just… You can’t as a normal thinking person… process how someone would do that,” said Bayer. “You wouldn’t even think about it.”

Hillcrest High principal Chris Bayer (CBS11)

Bayer said that Gilstrap-Portley took advantage of free school supplies and clothes. He repeatedly lied about his situation during sessions with counselors, according to Bayer.

“It’s difficult to fathom that it even happened,” said Bayer. “Still, deep down, it hurts to have someone betray you like that.”

Sidney Gilstrap-Portly was arrested on a charge of tampering with government records — a felony — after he was enrolled as a student at Hillcrest High School, claiming to be a displaced Hurricane Harvey evacuee.

The district confirmed he also played on the school’s basketball team during the school year.

Dallas ISD said it is promising to revisit its policies about situations like welcoming hurricane victims into the school district.

“This is a unique situation that shows us areas we need to take another look at when we open our doors to students in these situations,” said the district. “Safety is always our top priority, and we are reviewing our policies to strengthen district efforts while still helping those who are in need.”