Gio Toribio was sworn in as police chief for the day at the Ossining Police Department by Mayor Victoria Gearity.
A badge was pinned to his uniform, and he was then escorted around the station.
He went off to work with a police dog. Gio got to hold his leash and even watched him do tricks.
A number of agencies from Ossining banded together to make this special day possible.
"A lot of us are parents, we have children around this age, it's difficult to watch a child dealing with difficult stuff," a participant said.
Tuesday, Gio turns five years old.
While dealing with a form of lymphoma is a constant struggle, climbing up into the SWAT truck is sheer fun.
"I like being the police chief!" Gio said.
By all accounts, Gio was a little shy, but who could blame him with all of this attention.
He even got a visit by a helicopter from Hackensack, New Jersey.
Gio got to climb aboard, pretend to co-pilot and even met the pilot.
Gio has inspired thousands with his hashtag, #GioStrong, and his fighting spirit.
He even got the attention of New York Jets star Darrelle Revis, who once gave him a hug.