Police officer DiCandia was working in Times Square when he was met by Geraldine McKenna who was on holiday in New York City for the first time.
She had been waiting in line for Hamilton tickets for four days, only to find when she got to the counter that she was $20 short.
Officer DiCandia came to her aid, paying the last $20.
In a letter to the New York City mayor’s office, Ms Mckenna wrote: “We were totally overjoyed and beyond grateful when he opened his wallet and just handed us $20.
“My eldest daughter was crying when she was speaking to him.
“It was without doubt the best night that would not have been possible without Officer DiCandia’s generosity and kindness.”
The NYPD praised the officer for his actions on their Facebook page, writing: “Thanks to Officer DiCandia of the Times Square Unit, Geraldine from Ireland didn’t have to throw away her shot at Hamilton tickets!”
Many people took to Facebook to thank the officer for his kindness.
Nancy Tatz said: “Kindness goes a long way. This officers act will be remembered for years to come.”
While Tony Stone said: “Wow great job bro, what a cop for the people. Hero.”