Updated

Gunmen on motorcycles riddled Lasantha Wickramatunga's windscreen with bullets on his way to work in January. The 52-year-old Sri Lankan editor and frequent government critic died hours later.

In Pakistan, gunmen shot to death journalist Musa Khan Khel in February as he reported on a government deal with militants in the Swat Valley.

Both journalists are examples of how violence against the press often goes unsolved and unpunished. In a report released Monday called "Getting Away With Murder 2009," the New York-based Committee to Protect Journalists offered an "impunity index" of 14 top transgressor nations.

"Our findings indicate that the failure to solve journalist murders perpetuates further violence against the press," said Joel Simon, CPJ's executive director.

The group said its 2-year-old index ranks nations based on the number of unsolved journalist murders as a percentage of country population between 1999 and 2008. Unsolved cases are considered those with no convictions. Only nations with at least five unsolved cases make the list.

In descending order, ranked by the number of unsolved journalist murders per 1 million inhabitants:

—Iraq. Since the U.S. invasion in 2003, at least 88 journalists have been murdered, with no convictions.

—Sierra Leone. Most of the nine murders date to a civil war push on the capital by rebels in 1999.

—Somalia. Six murders are unsolved, including the shooting of the vice chairman of the National Union of Somali Journalists in 2008.

—Sri Lanka. At least nine killings remain unsolved. Violence has surged as reporters are targeted both by Tamil separatist groups and the military.

—Colombia. The country has had no journalists killed since 2006, but 16 killings from the past decade remain unsolved.

—Philippines. At least 24 murders are unsolved, including the 2008 shootings of two radio journalists.

—Afghanistan. The seven killings include four international journalists and three Afghans.

—Nepal. The five murders include four people who are thought to have been killed by Maoist rebels.

—Russia. Sixteen journalists who reported on official corruption, organized crime and unrest in the North Caucasus have been killed. All but one case remain unsolved.

—Pakistan. Ten unsolved cases, including three from 2008, highlight the country's rising insecurity.

—Mexico. Six cases are unsolved, including that of a radio host in 2008 who had campaigned against crime.

—Bangladesh. Seven cases are unsolved, including a crime reporter who was found decapitated in 2004.

—Brazil. Five unsolved murders linger from the past decade.

—India. Seven murders are unsolved, including a newspaper reporter shot by gunmen on motorcycles in 2008.