Following his funeral, many are wondering if his tragic death could have been prevented.
Jerf was a member of Raqqa is Being Slaughtered Silently, a citizen journalist group. And he wasn't the first from the anti-IS group to be targeted - two activists, Ibrahim Abdul Qader and Faris al-Hamadi, were shot and decapitated in the southern Turkish town of Urfa, near the Syrian border, on 30 October.
Local analysts noted that their deaths were made particularly horrific by the fact they were killed in Turkey, where they may have hoped to remain out of reach of the militant group that controls swathes of Syria.
"Syrians here are very worried. Are we safe? Will it happen again? But it seems to be a matter only concerning the Syrians living here," Mohammad Mosarea, spokesperson for Raqaa Is Being Slaughtered Silently, told The New Arab.
"The Turks are going about their daily lives as if nothing happened," he said.
The murders have led to questions concerning the protection that Turkey is providing to Syrian journalists and activists who have fled from IS.
"The Turkish government told our delegation with that they would increase security measures and provide a safe haven for all," Sherif Mansour of the Committee to Protect Journalists told The New Arab.
Yet Mansour feels Ankara's efforts leave a lot to be desired.
"Several journalists have reported armed groups operating on the border looking for journalists, especially international journalists, to kidnap," he said.
Accounts from international journalists who have recently attempted to make the perilous journey from Turkey to Aleppo suggest that militants in Syria also have the ability to kidnap on the Turkish side of the border.
|Friends and relatives of Naji Jerf hold his picture during his funeral in Gaziantep [AFP]|
Accordingly, Turkey should strengthen controls at the border to prevent militants from entering the country, said Mansour.
"Syrian journalists reported being threatened - two thirds of journalists [killed in this conflict] have been killed by targeted attacks by a specific group, rather than by cross-fire in a warzone," he said.
"At least half of those were threatened first."
These threats gave authorities more chances to intervene, said Mansour. But Turkey appears to have failed to make enough of an effort to prevent further attacks.
"Naji Jerf had received threats and the Turkish authorities said they would provide protection," Mansour said.
According to Jerf's friends and other journalists working in the city, threats to those working against IS have become common-place.
"IS sent threatens to most of the guys who work with Raqqa is Being Slaughtered Silently," said another journalist in Gaziantep. "They took pictures of the building of their apartments and told them 'we can reach you anytime'."
The journalist descibed Gaziantep city as "unstable".
|This is a security issue for Turkey as much as it is for us. The criminals can target anyone, even Turkish people
Mohammad Mosarea, RIBSS
"After that [the threats] Raqaa Is Being Slaughtered changed their places and some left to Europe."
Mansour said that Reporters without Borders had been facilitating Jerf's travel to France to claim asylum. He was due to travel to Europe with his wife and two young daughters the day after he was killed.
Raqqa is Being Slaughtered Silently, which has now lost three members in the country, also feel that Turkey could be doing more to prevent the killing of their affiliates.
"This is a security issue for Turkey as much as it is for us. The criminals can target anyone, even Turkish people," said Mosarea.
"But the Turkish officials are not serious about carrying out investigations," he said.
Turkey has carried out arrests on suspected IS militants, arresting a cell in Orfa and, on Tuesday, arresting three further suspected IS members, including a Briton.
Yet speculation concerning the possibility that Turkey "turns a blind eye" to militants travelling between the border, possibly due to oil interests, persists.
"The car that was used did not have a number plate. The shooter got out of his car in broad daylight, shot at his target and drove off," Mosarea said.
"Although this is a very important area for Turkish security, they are taking it as if it is purely a Syrian issue, not a Turkish one," he said.
Jerf directed the video "ISIL in Aleppo," which was shown on Al-Arabiya, a pan-Arab television news channel, also posted by Jerf on YouTube last week.
In the video Jerf documents IS human rights violations since they became present in Aleppo in 2013 until he left in 2014.
He was also active against the Assad regime. According to a report by Zaman al-Wasl Syrian intelligence services had issued four arrest orders for the late journalist.