Four-year-old Andrew has autism and sometimes things can get overwhelming for him. Andrew and his mother always take the Washington, D.C. metro to and from school, but during a recent rush-hour commute, Andrew became overwhelmed and started kicking, screaming and running around on the train platform.

"It does really hurt sometimes seeing the stares and the people that look at him. And he's so innocent. He's not trying to do it," Andrew's mom, Taylor Pomilla, told CBS Washington affiliate WUSA-TV.

Pomilla couldn't get her son to calm down, and while most people stared, one kind stranger stepped in to help. It was Metro Transit Police Officer Dominic Case, who went up to both of them to see what he could do.

Taylor Pomilla

"It looked like they were having a little hard of a time. And you know, I can relate as a parent myself, with a 4-year-old," Case told WUSA-TV. Not only is he a parent, but he receives annual autism sensitivity training through his job, so he was confident he could help Andrew.

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Case calmed Andrew down in a simple way. "Andrew was just holding my hand and just felt calm and I think, safe," he said. "And at that point, I figured I would just ride the train the whole entire ride with them."

What made the moment even more special was that Case gave Andrew the badge from his vest after their metro ride. Pomilla was touched by the officer's kindness and wrote a long Facebook post about him later that day.

"This officer COMPLETELY went out of his way to help Andrew. He honestly restored my faith that there are good people still left in the world," Pomilla wrote, sharing a photo of her son holding Case's hand.

"To that officer, I truly can not say thank you enough for your inmesurable [sic] amount of kindness and for making Andrews day (probably his whole year). Throughout the whole ordeal I didn't get his name, I think his vest said Officer D. Case," her post continued.

Officer Case calmed Andrew in a simple way — holding his hand. A photo of his king gesture went viral. Taylor Pomilla

She tagged several news outlets and the Washington Metro Police Facebook page, asking readers to "please find him and give him a raise! He deserves to be recognized for his incredible kind gesture, and especially for letting Andrew keep the police badge. Thank you thank you!!"

About a week later, Pomilla got to meet her son's savior and thank him in person. They reunited with Case on a D.C. metro platform, and Andrew immediately ran up to his new friend to shake his hand. WUSA-TV was there to capture the heartwarming reunion.

I wanted to take a few minutes to share something incredible that happened today. This afternoon I picked up Andrew from... Posted by Taylor Pomilla on Friday, July 19, 2019

Pomilla, as a single parent, said it was nice to see someone willing to go out of their way to help her. "I was just so frustrated, because I couldn't do anything for him. And for some reason, you were the star of the day for him," she told Case.

Pomilla wasn't the only one who felt thankful. Officer Case reciprocated the kindness he received. "It was probably the nicest thing someone's ever done for me," he said of Pomilla's sweet Facebook post. "So, I just appreciate the kind gestures as well."

It was a simple, kind gesture that ended up meaning the world to a single mom and her son. Pomilla's faith in humanity was restored, and Andrew made a new friend in Officer Case.