One juror called Kraft's testimony "some of the most compelling testimony" of the some 135 witnesses who took the stand during the nine-week trial.
Kraft testified that Hernandez told him he was innocent when asked whether he was involved in the June 2013 murder of Odin Lloyd.
Kraft was asked about the events of June 19, which was two days after the killing. The Patriots owner said he found Hernandez in a weight room working out at the team's facility and pulled him into an adjacent office for a private talk.
"He said he was not involved," Kraft said when questioned by the prosecution, which had said Hernandez was at a bar earlier in that evening, then drove to Boston with two friends, picked up Lloyd and killed him in an industrial park. "That he was innocent and that he hoped that the time of the murder incident came out because he said he was in a club."
That piece of testimony was key, jurors said.
"The one part for me was Aaron's alleged statement that he wished the time that Odin was murdered be made public because he was at a club at that time," one juror said. "To this day, we just went through a three-month trial, this is now a year and a half or two years later, and we still don't know the exact time of Odin's murder, specifically. So I don't know how Aaron would have had that information two years ago. Even today, after medical examiners' review, we still don't have that information."
Hernandez was convicted of first-degree murder in the case Wednesday and sentenced to life in prison without parole.
All 12 jurors and three alternates spoke to reporters after the verdict was announced.
They also said they were shocked by the defense admission that Hernandez was at the scene of the killing -- an admission that they said helped confirm that he was guilty.
They also described how the judge talked to them privately after they reached their decision and told them about other allegations and evidence not presented in the case. he jurors said that information also reaffirmed their feeling that they had made the right decision.
The Patriots signed Hernandez to a $40 million contract in 2012.
Within hours of his arrest, the team cut the former Pro Bowler.
Information from The Associated Press was used in this report.