New Zealand struggles to enforce gun-control law

CHRISTCHURCH, New Zealand — It was one of the defining moments as New Zealand grieved after a pair of deadly mosque attacks: a near-unanimous parliamentary vote in April to ban assault-style rifles and similar weapons.

The lawmakers’ move was immediately acclaimed by gun-control advocates worldwide as an example of decisive collective action in a nation unified in horror by the March 15 assaults in Christchurch that left 51 people dead.

Then the momentum began to slow.

Growing opposition from New Zealand’s pro-gun groups has complicated efforts to round up the now-banned firearms under a buyback program. Lawsuits are threatened.

Gun-control advocates argue that compensation rates may not be fair and warn of a possible spike in black-market sales.

The government, meanwhile, is faced with a sobering set of challenges over how to enforce the new law.