Graham Saunders turned the tap on his father for a good cause.
The nine-year-old nominated his father, Deputy Chief Mark Saunders, after taking the challenge himself.
Doting dad obliged in front of police headquarters where many of his staff looked on to the impromptu cold shower at the hands of Graham, and Constable Laurie McCann, who wielded the bucket.
"You could see him squinting with his mouth open," Graham said, delighting in his father's reaction to the icy water. "I think it was a bit scary for him."
Graham said he was very proud to take part in the ALS challenge and include his father in the worthy cause, despite the shock of the cold water.
"You did get a strong sensation when you do it," said Graham, who took the bucket challenge alongside Constable Joel Houston and his horse, Tecumseh. Houston himself took the plunge via a small front loader used in the horse barn.