The senior Bharatiya Janata Party leader and former Gujarat home minister was shot dead in an Ahmedabad park on March 26, 2003.
But Pandya's family is dissatisfied with the verdict.
His widow Jagruti Pandya told rediff.com, "I have great respect for the Indian judiciary, but I cannot accept this judgment because it is based on an incomplete investigation."
She revealed that the Central Bureau of Investigation neither recorded her side of the story nor asked her to appear before the POTA court.
"I was perhaps the last person to speak to my husband before he was killed. He left home for his morning walk and was killed while he tried to get out of his car for his walk. Despite several pleas, I was never called to give a statement by the investigating agency. I could have provided some vital information," she said.
The investigation of the case was first conducted by the Crime Branch in Ahmedabad under the supervision of D G Vanzara, the senior police officer who is currently under arrest for his alleged involvement in the Sohrabuddin Sheikh fake encounter.
The Pandya murder case was later handed over to the CBI after protests from civil liberty groups.
After her husband's death, Jagruti Pandya has struggled to educate her two children.
She feels sad that neither the BJP government in Gujarat nor the party has done anything to keep Haren Pandya's memory alive.
With the help of her husband's supporters she erected Pandya's statute at Nehru Nagar Circle in Ahmedabad.
"My husband lived and died for the BJP. His Ellis Bridge constituency brought the highest percentage of BJP votes (over 73 per cent) in Gujarat," she said.
Vitthalbhai Pandya, her father-in law, has run a crusade these last four years to get justice for his slain son.
He told rediff.com, "Even the CBI depended on Vanzara's investigation. He interfered all the time in the CBI's functioning."
After his son's death Vitthalbhai Pandya alleged that Chief Minister Narendra Modi was involved in the plot to murder Haren Pandya. But he does not have evidence to substantiate this serious allegation.
When asked to furnish the evidence against Modi, Vitthalbhai Pandya alleged, "My son was a political challenger to Modi. He was capable and popular but Modi didn't give him a ticket to fight the election. He was targeted because
"How is it possible," she asked.
"For two-and-a-half years," she said, "the mobile and phone records of my husband were not produced by the CBI. The CBI investigating officer admitted during his cross examination that the CBI had procured these records as early as March 30, 2003, but he admitted in open court that the CBI has no idea where the original printouts are. Where did the original phone records disappear?"
"As his widow," she said, "I request the Gujarat government to please intervene and seek a re-investigation in the Haren Pandya murder case. I will soon meet the honourable chief minister and request him to seek a re-investigation in the case. A re-investigation is a must for the truth to come out."