A sex offender feared by his Abbotsford neighbours is becoming a target himself as vigilantes have launched a campaign of vandalism that last night caved in a ceiling in his home.

Abbotsford police are stepping up patrols and video surveillance after now counting 15 acts of vandalism, which they suspect are by angry residents looking to try and get James Conway moved out of their neighbourhood.

"Last night, what happened in the early morning hours, that was completely over the top," said Abbotsford's Const. Ian MacDonald.

Someone ran a garden hose into a vent at the top of the property on Juanita Place, which flooded the interior of the property and collapsed a ceiling.

A photo shows insulation pouring out of a ruptured ceiling, with water damage that police estimate is in the tens of thousands of dollars.

Previous attacks have included throwing rocks, pouring concrete, padlocking doors, and smearing the property with paint or oil.

The house is run by an agency contracted with Community Living BC as a residence for mentally challenged adults. Conway lives there along with another man and a 24-hour caregiver.

Any of those three people could have been killed if the ceiling had collapsed on them, said homeowner Brian Vos.

"I'm worried there could be loss of life," Vos said, adding that he has been targeted online by angry neighbours calling him names over his decision to rent the property to the provincial agency.

Vos said he rented the house to the agency to help people, and was shocked when he heard that the ceiling had caved in.

"It's a horrible feeling. And it's worse for my kids. That's the house they grew up in," he said.

Vos said the house is still habitable. He also has concerns about the danger posed by Conway, but has been convinced by police that the measures to protect the community, including an ankle bracelet and 24-hour supervision, are enough.

"I've decided that I'm not going to evict them. The (neighbours) have pushed me to the point that they've shown me they aren't reasonable people," he said.

Kim Iverson, who has organized protests against Conway, said she's still hoping that a plan by Abbotsford's mayor to evict Conway on zoning grounds will succeed.

"I'm not saying I think vandalism is okay, but I'm not losing any sleep over it," she said.

Const. MacDonald said the agency is tired of wasting police resources on multiple vandalism calls, and intends to investigate the most recent incident by reviewing surveillance camera footage.

"Certainly we would hope people would defer to adhering to the laws, behaving themselves, and avoiding this type of behavior," he said.

MacDonald said he believes protections are in place that would stop Conway from breaching his conditions.

Conway was convicted in 2000 of a sexual assault, and then of sexual interference of a person under 16 in 2005. He breached conditions several times, including in February 2015, where he was arrested for sitting next to a young girl on a TransLink bus.

There are almost 300 registered sex offenders living in Abbotsford, police said.