The judge overseeing the criminal case against former President Donald Trump has received dozens of threats in recent days, police sources told ABC News.

Trump himself has repeatedly lashed out at New York Supreme Court Judge Juan Merchan both before and after his court appearance, calling Merchan and Merchan's family "Trump hating" in a speech hours after he was arraigned on Tuesday. Merchan previously oversaw the tax fraud trial of the Trump Organization that ended in a conviction.

Most of the threats against Merchan are in the form of harassing calls and emailed death threats, the sources said.Over the past weeks we have continued to evaluate and assess security concerns and potential threats and have maintained an increased security presence in and around courthouses and throughout the judiciary and will adjust protocols as necessary,” a spokesman for the Office of Court Administration told ABC News.At Trump's arraignment in Manhattan on Tuesday -- on 34 felony counts of falsifying business records to which he pleaded not guilty -- prosecutors voiced alarm at his "recent public statements threatening our city, our justice system, our courts and our office."Assistant District Attorney Christopher Conroy said then that Trump's posts on social media and elsewhere, including one warning of "potential death and destruction" and those directed at the grand jury, at prosecutors and others were why a protective order was needed to limit his public comments, particularly around what he may learn about the prosecution's case through discovery.