A 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.