A Dutch police chief has called for an end to "paedophile hunting" after a 73-year-old retired teacher was beaten up by teenagers and died of his injuries.
Oscar Dros said there was a risk more people could die and he appealed for justice to be left to the authorities.
The man from the eastern city of Arnhem was lured into having sexual contact with a minor while in a gay chatroom.
Authorities said he was aware the boy was underage. But there was no evidence of past sexual contact with minors.
The Arnhem attack is the latest in a series of 250 incidents involving so-called "paedophile hunters" in the Netherlands, reports say.
What happened in Arnhem
Reports say the group of teenagers had come up with the idea of hunting for a paedophile after reading stories elsewhere in the Netherlands.
The former teacher arrived at an agreed meeting point on 28 October and was then followed as he made his way home. He was beaten up by a group of boys and died later in hospital.
Mayor Ahmed Marcouch has spoken of an "awful crime" that has had an impact on the local community. Dozens of neighbours, friends and former pupils took part in a ceremony to remember the victim last weekend.
The fifteen-year-old's lawyer told local website De Gelderlander that the idea of hunting paedophiles "happened out of boredom in this corona time". His client had got carried away but did not himself take part in the attack.
Jamil Roethof argued that the teenagers had only wished to confront the man and had no premeditated plan to attack him. He suggested he had died of a fall.
Seven teenagers were arrested, six of them under the age of 18, and two have been held in custody.
What do police say?
East Netherlands regional police chief Oscar Dros appealed to Dutch citizens to "stop paedo-hunting; stop detaining; stop provoking - leave this to us."
Mr Dros told Algemeen Dagblad newspaper that since July some 250 incidents had been registered involving self-styled hunters, and there were probably many more. The practice has now been banned by police and public prosecutors.
People had been forced off the road, assaulted, threatened and publicly shamed on the internet, he said.
Facebook groups have sprung up across the country, with names like pedohuntnl, and some have attracted thousands of members.
One group member told public broadcaster NOS that "we're doing this to protect children".
Minutes after going into a chatroom, he claimed, five or six men would try to meet up with you, knowing full well you were a minor. "That's just not right."
Similar groups have appeared in the UK, prompting one assistant chief constable to say the overall activity of such groups was "not positive".
The Dutch police chief said such vigilante behaviour "has no effect, because the evidence these citizens believe they have is often paper thin".
He knew of not one example that had led to a paedophile being convicted.