( CNN ) Diego Lagomarsino is among the few who can offer clues about the puzzling death of Argentine prosecutor Alberto Nisman . The IT security expert was one of the last to see Nisman alive . Nisman was found dead in his apartment days after filing a report accusing the country 's top leaders of covering up Iran 's involvement in Argentina 's worst terrorist attack . It looked like a suicide , but now even the government has doubts that is the truth . So when Lagomarsino decided to address reporters on Wednesday , it should have been an unequivocally illuminating event . But like so much of the information surrounding Nisman 's mysterious death , seeds of doubt had already been planted . In addition to being an assistant to Nisman , Lagomarsino is the one who gave the prosecutor the gun that ended his life and is the only person charged in connection with his death . Lagomarsino faces up to six years in prison if convicted of providing Nisman with the gun . With this hanging over his head , Lagomarsino broke his silence , saying that he committed no crime and that he let Nisman borrow the gun at the prosecutor 's insistence . Nisman was fearful about his safety after he filed his report in court and was distrustful of even the security guards that were assigned to protect him , Lagomarsino said . The prosecutor had called Lagomarsino , who had become a family friend through the IT work he did for them , before dawn on January 17 . Nisman asked him to come over to his apartment immediately , Lagomarsino said . Lagomarsino recalls seeing documents splayed out on a table and an anxious Nisman spilling his fears . The prosecutor was worried about repercussions for the accusations he levied against the government . He alleged that President Cristina Fernandez de Kirchner and Foreign Minister Hector Timerman , among others , conspired to cover up Iran 's involvement in the 1994 bombing of a Jewish community center in Buenos Aires in exchange for a friendly trade deal . In the days after he filed the complaint in court , Nisman did n't even venture out to buy groceries . He had his mother do that for him , Lagomarsino said . `` I am more afraid of being right than being wrong , '' the IT engineer remembers Nisman telling him that morning . He was afraid that his daughters were in danger , Nisman told Lagomarsino . The prosecutor said he did n't trust his security guards , and asked Lagomarsino if he had a gun he could borrow . Lagomarsino went back home and thought about the request . When Nisman called again , insisting that he bring the weapon over . According to Lagomarsino , Nisman claimed he would not use the gun and only wanted to have it in his glove box in case of an emergency . So Lagomarsino returned to Nisman 's apartment , handed him the weapon , and then left . He texted Nisman later that afternoon to check in on him . The prosecutor never replied . Nisman , who had been investigating the 1994 bombing of the Argentine Israelite Mutual Association ( AMIA ) that killed 85 people , died from a gunshot wound to the head . The gun that Lagomarsino had given him was near the body , along with a shell casing . His body was found on January 18 , the day after his conversation with Lagomarsino , and the day before he was to testify before lawmakers about his allegations . An autopsy was performed the next day . President Fernandez was quick to call it a suicide but changed her story a few days later . A test found no gunpowder residue on Nisman 's hands , as would have been expected if he had pulled the trigger . On Wednesday , Nisman 's body was returned to his family after his ex-wife declined to have additional tests conducted on the body , the state-run Telam news agency reported . The prosecutor 's funeral is scheduled for Thursday . Even before Nisman died , Fernadez 's government vehemently denied that it had covered up anything relating to the 1994 bombing . The government 's Cabinet chief has said that Nisman was swayed by information from Antonio `` Jaime '' Stiusso , a former Argentine intelligence chief . Stiusso was ousted from the intelligence agency in December . Government officials have implied that rogue intelligence agents misled Nisman to attack Fernandez and then killed him when they no longer needed him . Many of the small details in the case fuel the conspiracy fire . In the days after Nisman 's body was found , state media published what it described as a social media message from Nisman to friends explaining that he had to cut a vacation to Spain short so he could return to Argentina and file the report against the President . On Wednesday , the prosecutor investigating Nisman 's death , Viviana Fein , told reporters that there is no evidence that Nisman suddenly changed his plans . Records show that his return from Spain had been planned weeks before . There have also been reports linking Lagomarsino to the former intelligence agent Stiusso . The IT man 's lawyer denied that the two knew each other . Argentina 's President pushes intelligence shakeup after Nisman scandal .
The owner of the gun that killed Alberto Nisman explains his side of the story . Diego Lagomarsino gives new details about Nisman 's puzzling death . He is also the only person charged in connection with the death .