A "fatal blow" will have been dealt to Iraqi government control if Prime Minister Mustafa Al Kadhimi does not catch those who ordered the killing of scholar Husham Al Hashimi, experts said.
The Iraqi political and security expert was shot dead at point-blank range by unknown assailants as he parked his car outside his house on July 7.
Mr Al Kadhimi pledged to hold a transparent investigation into the killing and said no one was above the law.
A week has passed and the government has not announced any developments.
Toby Dodge, an Iraq expert and friend of Al Hashimi, said failure to bring to justice those responsible for his assassination would be a challenge to the state’s authority.
"A man so loved, admired and respected, and so close to the supposedly most powerful politicians in Iraq ... they've got to catch his killers and those who ordered his murder," Mr Dodge told The National.
He said the leaders of the organisation that ordered the killing must receive justice.
“This was designed as a challenge to the prime minister, and if he can’t meet that challenge then it’s a huge blow to the prestige and capability of the Iraqi state,” Mr Dodge said.
Al Hashimi’s murder sent shockwaves around the world and was interpreted by many as a challenge to the prime minister’s pledges to defeat armed groups.
“A lot of people want to see action. Can the government uphold justice?” asked Sajad Jiyad, an analyst in Baghdad.
“Is it possible to show that the state is still in control of security? These are serious questions and I’m not sure if the prime minister has the answers.
“You can see from the horrible pictures of the video [of Al Hashimi's murder] how easy it was to pull off the operation.
"There's so many checkpoints and security forces all over Baghdad, yet the killers managed to escape. This is a huge concern."
Al Hashimi was an adviser to Mr Al Kadhimi, who since assuming office in May has taken a tougher stance against rogue elements of the Popular Mobilisation Forces, an umbrella group of various militias.
“It doesn’t look like the government is going to be able to stop it from happening again,” Mr Jiyad said.
Al Hashimi reportedly told friends he had received threats from militia groups in the weeks before his death.
But the friends said he brushed the warnings off, ignoring pleas to leave Iraq or hire security staff and move to a more secure location.
Al Hashimi was recognised for his expertise on Al Qaeda, ISIS and the Iran-backed armed groups that operate in Iraq.
Government officials, diplomats and journalists sought his insight on controversial topics.
Al Hashimi was strongly in favour of the protests that erupted across Baghdad and Iraq’s Shiite-majority south in October, which accused the government of being corrupt, inefficient and beholden to Iran.