McCreary, 61, was arrested without incident outside of a Park Street house in the southeastern New Brunswick city at 11:25 a.m., according to the police.
The Abbotsford Police Department is crediting tips from Moncton citizens and social media activity in the city for helping to catch him.
Police officers had been trying to track McCreary down for three months. Earlier this week, the police force's Canada-wide manhunt had been narrowed to Moncton.
Once police announced they believed McCreary was holed up in Moncton, the public's response was amazing, said Const. Ian MacDonald.
The department received up to 15 phone tips a day, he said.
"It's unusual for the public information officer in Abbotsford British Colombia to receive 10 or 15 phone calls a day for four or five days straight from citizens that live in a city on the other coast," MacDonald said.
"It's almost unprecedented that I would get that number of calls over a number of days."
Facebook users shared photo
The police force's Facebook and web sites also exploded with activity, he said.
"It started to go off the charts as far as responses that we got specifically from Moncton."
About 3,000 people shared McCreary's photo, said MacDonald. That's 300 times more than any other case he's handled, he said.
Abbotsford police shared the information they received with Codiac RCMP. "And there was a series of phone calls that sort of honed in and created a series of hot spots where we felt McCreary could be," said MacDonald.
The Abbotsford Police Department is now making arrangements for McCreary's transfer back to British Columbia.
Police said they believed McCreary fled British Columbia on July 17, just before he was going to be picked up on the 18 charges.
There is a publication ban on the details of the charges, but they include 13 sexual offences, four counts of aggravated assault and one of forcible confinement.