The formal campaign for Cambodia's general elections on July 27 is still several months away, but if election violence is any measure, the contest has already started.
The latest killing, that of Om Radsady, an adviser to the royalist Funcinpec party, has left many Cambodians stunned and fearful.
The Interior ministry says that Om Radsady was killed for his mobile phone.
But Peter Leuprecht the United Nations human rights envoy in Cambodia, says it was an assassination and possibly a sign of escalating election violence.
Because of the weak judiciary, when powerful people commit a crime or illegal act, they are rarely punished by the court
Thun Saray, human rights activist
He warned the country's National Election Committee against being a paper tiger, urging the committee to penalise those responsible.
"I sincerely hope that this trend of killings before elections will at last discontinue in Cambodia and I sincerely hope that the authorities will do everything in their power to prevent such acts of violence.
"If, nevertheless, such acts occur, the law must be applied and these cases must be seriously investigated, and those responsible must be punished," he said.
Statements about what should be done mean little on the streets of Cambodia, where renewed tension stems from the latest killing and from anti-Thai riots in January which are widely seen to have been orchestrated for political purposes.
The National Election Committee is around the corner from the Thai embassy, which was burned and smashed by rioters angered by reported claims over their ancestral heritage at the temples of Angkor.
The NEC's chairman, Im Sousedy, told the BBC that he was still waiting for the government to explain if there were political motivations behind the violence.
Bangkok has demanded almost $50m dollars in compensation.
Some say Cambodians have learnt a rare lesson of responsibility from the riots.
But, according to human rights activist Thun Saray, it is just a blip in a deeply-rooted culture of impunity, where violence and power are natural partners.
"The issue of impunity is still widespread. Because of the weak judiciary. When powerful people commit a crime or illegal act, they are rarely punished by the court," he said.
Launching Cambodia's poverty reduction strategy this week, Prime Minister Hun Sen talked about the need to protect human rights and strengthen peace, stability and social order.
Cambodia has a set up a new, streamlined election committee which says it is determined to run the July poll as close to free and fair as it can get.
But then there is the question of what happens after the vote.
While it is widely believed Hun Sen's People's Party will win, there is already talk of a split in its ranks.
And if either FUNCINPEC or the opposition Sam Rainsy Party poll strongly, there will be a need for negotiations to form a government.
And, too often in Cambodia, negotiations are done with a gun.