(CNN) -- Unidentified gunmen shot and killed a freelance journalist outside his home in Mosul on Thursday, the Committee to Protect Journalists said.
Hilal al-Ahmadi, 57, a freelance journalist for more than 30 years, was gunned down as he headed to work, the group said.
His writings focused on financial and administrative corruption, according to the group.
"It is time for the government to take the long-delayed initial steps toward ending a years-long record of impunity for journalist murders in Iraq," the committee said while calling for an investigation into the killing.
From 2003 to 2008, Iraq was the deadliest country for journalists, the committee said. After a drop in violence in 2009, attacks against journalists picked up again in 2010 when at least six were killed, it said.
According to the committee's 2010 Impunity Index, Iraq ranked first in a list of countries were journalists are regularly killed without their killers being prosecuted.
"Not a single journalist murder since 2003 has been seriously investigated by authorities, and not a single perpetrator has been brought to justice," the group said.
There was no immediate reaction from the Iraqi government.