Little progress has been made in the investigation, which may take weeks, if not months or years to complete.
The suspected gunman, who has been caught, was named by police as Kyi Lin. He told police that an acquaintance had offered to pay him to buy a car if he carried out the job.
While tens of thousands turned out for Ko Ni's funeral on Jan 30, many people are closely watching how authorities investigate a killing which President Htin Kyaw's office says is an attempt to "undermine the country's stability".
Because of the high-profile nature of the victim and partly because of the international community's interest, the chief of the Myanmar police force, Maj Gen Zaw Win, has taken charge of the probe, which is being handled by the police's criminal investigation department.
Ko Ni was known for opposing legislation restricting interfaith marriages and conversions under former president Thein Sein, and had also helped draft a bill to limit religious hate speech.
As a constitutional law expert, he had also spoken out about the powerful role which the military retains in governing the country, despite handing over power to the NLD government in April last year.
Despite all these facts, there are certain things that are puzzling to many ordinary citizens and observers alike. The first question concerns the silence of the country's de facto leader Aung San Suu Kyi.
She has neither said anything officially nor attended the funeral service of Ko Ni, which drew an estimated 100,000 mourners, including family members, lawyers, NLD activists and members of Yangon's diplomatic corps.
Not only was Ko Ni a prominent lawyer, he had been a trusted adviser to Suu Kyi's NLD Party on exploring ways to amend the military-drafted constitution, especially Article 59 (f) which bars Ms Suu Kyi from holding the country's highest office.
That article says the president, one of his or her parents, spouse or children, should "not owe allegiance to a foreign power, not be a subject of a foreign power or a citizen of a foreign country".
Mr Suu Kyi's former husband, the late Michael Aris, was British.
Ko Ni's constitutional expertise was crucial in circumventing the controversial clause by creating the post of state counsellor, which officially answers to the president but in reality is a powerful spot at the top.
In her capacity as state counsellor, Ms Suu Kyi has control over the different ministries of the government, except for the three ministries constitutionally guaranteed for the military -- home, defence and border affairs.
One reason for Mr Suu Kyi's silence could be that she would like President Htin Kyaw's office to speak on her behalf, which would convey to the world that despite her de facto position, she respects and follows the protocol of keeping the president's office at the top.
One other possible explanation is she is restraining herself from making comments for fear they could be misconstrued by many of the majority- Buddhist population amid heightened tensions between Muslims and Buddhists, especially in Rakhine state.
Another possible explanation is that since the home ministry, which is controlled by the military, has assured it will conduct a through investigation, Ms Suu Kyi is letting the law take its own course.
It could also just be that she is awaiting for further details before making any public comment.
While her silence remains a question, there is a possibility the Muslim population within and outside the country could accuse Ms Suu Kyi being political and opportunistic if she remarks on the demise of someone who worked relentlessly for her political victory.
It also remains to be seen whether people of vested interest orchestrated the assassination of Ko Ni or if it was part of a larger conspiracy. For example, was he a political victim of his efforts to replace the undemocratically drafted constitution with a more democratic one?
Another possibility is that he is a victim of some religious fanatics because of his opposition to the legislation restricting interfaith marriages and conversions under former president Thein Sein, or for helping draft a bill to limit religious hate speech, or something related to the Rohingya conundrum.
Though Ko Ni belonged to the minority Muslim population, there was no evidence that he was using his professional role as a lawyer and trusted advocate of the NLD Party to advance or promote his own religion and vice versa.
Regardless of the motive behind the murder, it is a blow to the country's democratisation process. In a country where the rule of law still is a major problem, Ko Ni's assassination could cause fear and anxiety for potential law practitioners and reformers.
The NLD government and the military must deliver justice to the injustice and be answerable to the many questions that remain unanswered.
More importantly, all political stakeholders, including the international community, should continue to help the Myanmar government achieve peace and stability in the country.
Nehginpao Kipgen is an assistant professor and executive director of the Centre for Southeast Asian Studies, Jindal School of International Affairs, OP Jindal Global University. His writings have been published in more than 30 countries on five continents – Asia, Africa, Australia, Europe and North America.