JOIN USA federal jury hearing the case is now set to begin its final deliberations to decide Rana's fate after the closing arguments were presented in the court that is set to deliver the verdict.
Rana himself, however, chose to remain silent and did not testify at his trial that stretched for a fortnight.
The 50-year-old doctor is charged with providing material support to terrorists by providing cover for main accused Headley while he laid the groundwork for the Mumbai attack in which 166 people died in a two-day siege.
The government prosecutors argued that there was overwhelming evidence of not only Rana having the knowledge of but also assisting and providing material support to his childhood friend Headley in carrying out the attack in November 2008.
They pleased for justice for the victims of the ghastly terror attack in India.
"Those who died in Mumbai demand justice. You (the jury) will find the truth... this man knew that his trained terrorist friend (Headley) was bent on killing people," US attorney Daniel Collins said to the 12-member jury in his final arguments in a packed court room.
Not only media persons from various parts of the world, but also government officials, community leaders and Rana's family members were present in the court.
Sitting in the court room, Rana, who has maintained silence throughout the proceedings looked a bit tensed as the trial came to end.
"What happened in Mumbai could have happened in Copenhagen. 164 people died in flurry of bullets (in Mumbai). Such horrific acts take place with help of a number of people... weather you carried a gun or did something helped in the planning or had the knowledge," Collins said.
Rana's defence, on the other hand, asked the court not to get fooled by Headley, who they said had fooled everyone in the world including the FBI.
In an emotional appeal, defense attorney Patric Blegen pleaded that his client was a religious man and was duped by Headley who used him for executing his terrorist plans.
"Headley fooled everyone. Don't let Headley fool you. Please do not convict Rana in this case," Blegen pleaded.
He said Rana was simply a businessman who was interested in expanding his business overseas including in Mumbai, Lahore, Karachi and Denmark.
Headley exploited Rana's business expansion plans and duped him as he used the business to serve the terrorist interest of both the ISI and Lashkar-e-Taiba, he argued.
"He (Headley) lies under oath. He lies to accomplish his goals," the defense attorney said.
"Headley sacrificed Rana for himself and his family," Blegen argued as he reiterated that he and his team presented before the court over the past two weeks that Rana had no knowledge about Headley's terrorist intentions.
Rana's lawyer Charles Swift said the government has to prove "beyond reasonable doubt" that Rana was gulity.
The trial saw LeT operative turned government witness Headley testifying for five days and making revelations about the role of ISI in the Mumbai incident.
But Swift said that he wouldn't believe Headley on anything because he was manipulative.
"First Rana went to Mumbai before the attacks which makes no sense and shows that Rana did not know of the attacks," Swift said.
"Second, when Headley was preparing for the Denmark attacks, Rana suggested that his 75-year-old business partner Raymond Sanders come along. Again that is not indicative of any knowledge," Swift said.
"We think that actions speak louder than any of the words in this case and if you put those things together there is clearly reasonable doubt," Swift said.
He said Headley was a "predator" who preys on people and that he has been doing it for 30 years.
"Headley changed his stripes, he did Dr Rana in and that's and extraordinary change in character and I think what we've learned from this trial is that David Headleys don't change," Swift said.
He said Rana had no knowledge of what Headley was planning with the ISI people. The Army doctor, who was declared a deserter after refusing a glacier posting, has claimed that Headley was using his influence with the ISI people to make it possible for him to return to Pakistan.
"The emails with Rana, Headley and ISI was there. There was no e-mail from Pasha, Sajid or any terrorist organisations.
"E-mails show Dr Rana was systematically cut out from any information that might be there," Swift said.
Asked about Rana's state of mind, Swift said Rana was calm. "He (Rana) is a religious man. Now is time for prayer and that's where he's at. He has put his trust to the jury," Swift added.
"He has put his trust in two things. He came to America because he believed in the American system and he believes in God," Swift said.
"In American jury system is like anyone else. It is like electing the Pope. When the smoke comes out of the chimney, the journalists will know but before that we won't know that's the way the American system works. This could be over in an hour and we could all be having a conversation next week and the week after," Swift said.