New York: Monday, as law enforcement officials stepped up security measures in anticipation of a potential indictment and as fellow Republicans staked out positions in a criminal investigation anticipated to reshape the 2024 presidential race, a grand jury heard testimony from a potential final witness in the investigation into Donald Trump. Robert Costello's testimony came as the grand jury that has been looking into Trump over hush money payments made to a porn star during his 2016 campaign for months seemed to be wrapping up its investigation. Costello is a lawyer who had a falling out with the key government witness in the Trump investigation. As a key witness in the investigation who has already testified in front of the grand jury numerous times, Michael Cohen, Costello was asked to appear after claiming to have information casting doubt on his credibility. Also Read: Sri Lankan Rupee to appreciate once country enters into IMF deal: President Although there were no overt indications that Costello's presence had altered the course of the grand jury investigation, it was anticipated that the former president would use his testimony to indirectly argue that he shouldn't be charged with a crime. Although Cohen had been available for more than two hours, his attorney claimed Monday that Cohen was not required to refute the testimony. Cohen, who is also a lawyer, had previously received legal assistance from Costello. After testifying before the grand jury, he held a press conference where he informed the media that he had come forward to offer Trump's defence information and to make it clear that he did not think Cohen, who had admitted to federal crimes and served time in prison, could be trusted. If they have compelling evidence and want to pursue Donald Trump, that is their prerogative, according to Costello. But Michael Cohen is not a reliable source of proof. Later on Monday, in response to Costello's assertions, Cohen stated on MSNBC that Costello was never his attorney and that "he lacks any sense of veracity." The testimony came two days after Trump urged supporters to protest his potential arrest and stated that he anticipated to face criminal charges. The former Republican president criticised the New York investigation in several social media posts over the weekend, using particularly hostile language towards Democrat Manhattan District Attorney Alvin Bragg. Although it's unclear when prosecutors might finish their work, New York's law enforcement has been making physical preparations in case there is any unrest related to a potential indictment. A truck from the New York Police Department arrived early and started unloading portable metal barricades that could be used to close off sidewalks or streets. Also Read: PM Modi holds bilateral talks with Japan PM Kishida, Thanking for G7 summit invite After the FBI searched Cohen's house and apartment in 2018, Costello served as Cohen's legal counsel for a brief period of time. Cohen was being looked into at the time for tax evasion as well as payments he helped arrange in 2016 to silence two women who claimed to have had sex with Trump. The loyalty of Cohen, a seasoned attorney and fixer for the Trump Organization who once boasted that he would "take a bullet" for his employer, to the president was a question for several months. In relation to the payments to porn star Stormy Daniels and model Karen McDougal, which Cohen claimed were ordered by Trump, Cohen ultimately made the decision to enter a guilty plea. He has been a vocal critic of Trump ever since, appearing before the Manhattan grand jury and then Congress. Cohen has been called a liar by Trump, who has denied having sex with either woman. When it became clear that Cohen was no longer in Trump's corner, Costello ended their relationship before Cohen entered a plea. Since then, Costello, a seasoned lawyer in New York, has defended Trump allies like his former political advisor Steve Bannon and his personal attorney Rudy Giuliani. Even as the New York investigation moves closer to its conclusion, Trump is also dealing with criminal investigations in Atlanta and Washington that, when combined, pose serious legal risks and have the potential to derail the Republican presidential primary in which Trump is still a front-runner. Some of his likely adversaries have attempted to strike a balance between branding a prospective prosecution as politically motivated and avoiding endorsing the conduct in question. In a move that is likely to escalate their already-heated political rivalry, Florida Governor Ron DeSantis, a predicted GOP presidential candidate, criticised the investigation while also taking one of his first shots at the former president. At a press conference in Panama City, DeSantis said, "I don't know what goes into paying hush money to a porn star to secure silence over some kind of alleged affair. I'm unable to comment on that. But he continued, "What I can speak to is that if you have a prosecutor who chooses to look back many, many years in order to try to use something about porn star hush money payments, that's an example of pursuing a political agenda and weaponizing the office. Crimes happen every single day in your jurisdiction. And I believe that is fundamentally incorrect. Also Read: Indian-origin attorney to name for District Commissioner post in the US In an interview with ABC News last weekend, Mike Pence, the former vice president who is anticipated to run against Trump for the Republican nomination, called Trump's actions on January 6 "reckless" and predicted that history would hold him responsible. He nonetheless repeated the former president's assertion that a political prosecution would result from an indictment. Pence stated, "I am confident that President Trump understands how to care for himself. Also, he will. But that still doesn't make the politically motivated prosecution of a former president right.