The government has been criticised for failing to protect journalists and political activists against extra-judicial killings which have occurred since the restoration of democracy in 1986.
The country's National Union of Journalists said 49 reporters have been killed since 2001, with at least 12 in 2006 alone.
Jose Torres Jr, chairman of the union, urged the government to take a tougher line on those who attacked journalists.
"Official inaction has bred a culture of impunity and emboldened those who seek to stifle freedom of the press and of expression in this country,” he said.
He called on police to "once and for all, show the world these killings are being addressed by the government".
Pastolero was a radio journalist and editor of several publications before launching his own weekly, the Lightning Courier.
Eva Marie, his daughter, said he had never mentioned death threats.
The New York-based Committee to Protect Journalists said the Philippines and Afghanistan had the highest journalist deaths in the region last year with three deaths each.
Both countries were globally ranked second only to Iraq, where 32 journalists were killed in 2006.
Tallies of the number of slain reporters in the Philippines differ from group to group.
Philippines police said they have recorded 26 journalists killed on duty since 1986. According to police, many other cases were not work-related and involved land disputes or personal grudges.