As the investigation into potential links between Donald Trump's 2016 Presidential campaign and the Russian government continues down new avenues, questions are arising regarding both the obtaining and review of evidence.

A January 2018 memo from President Trump's then-lawyer John Dowd specified that the Trump campaign provided special counsel Robert Mueller with over 1.4 million document pages, while the White House turned over 20,000. The investigation has since expanded, with Mueller subpoenaing the Trump Organization for documents and making a referral that led to the FBI's seizing of documents from President Trump's personal attorney, Michael Cohen.

While the overall number of documents remains undisclosed, as do the methods employed in the review process, Andy Wilson, CEO at e-discovery company Logikcull, said that likely, “the vast majority of the data is junk.”

“That's the biggest problem that investigative teams face today,” Wilson said. “The signal isn't necessarily getting stronger, but the noise for sure is.”

Wilson's view toward investigation expediency is common among e-discovery professionals. During the 2016 investigation into Hillary Clinton's emails, many noted that the FBI's review process could be carried out relatively quickly with technology commonly utilized in civil litigation.

“If I'm an investigator and I have all this Trump data or Cohen data, I can [use technology to] quickly see common stuff like Amazon emails or fantasy football stuff, and I can run some keyword searches to get that noise out of the way. What ends up happening—and this is very common now—when people do that and they cull the data, the signal becomes crystal clear,” Wilson said. “Once you get rid of that noise, then all you have is potential signal.”

In Wilson's estimation, document collection and review with about 1.4 million documents and two reviewers would take between 24 and 48 hours. Yet Jonathan Redgrave, partner at Redgrave LLP, said that taking more time is expected, as what's unfolding is “a natural progression of an investigation, where people are looking at all sorts of data sources in terms of collection.”

“There's a reason why people take time to do things right. There's a process, even with data collection and analytics. It's not a simple, easy button,” Redgrave said. However, he noted that there's likely a large amount of unstructured data, potentially emails, text-based messages and audio, as well as structured information like banking and financial records. In handling these types of data, he said that analytics could be useful in demonstrating “who's talking to whom,” while computer-assisted learning techniques could identify relevant concepts as well as “code names, code words, and things like that.”

Yet Redgrave believes the Trump investigation might not be “the most document-intensive case. You're not trying to pull together a 15-year Ponzi scheme kind of thing. They're looking at special communications in potential influence, or potential ways people may have conspired or worked together.”

“Ultimately, there's just a lot of high-level human intelligence that has to be applied to discern and used to say, 'What was really going on here?' to put forward to a grand jury or some other process on the criminal side,” he added.

There are also legal issues around evidence collection to take into consideration, particularly regarding the seizure of Cohen's records in April.

“There's an added complication there to the extent that what [investigators] are looking for came from Cohen's office or residence,” said retired U.S. Southern District of New York Magistrate Judge Frank Maas. “There has to be basically a separate privilege team to look through the privileged materials and see whether there's a basis for concluding, a) there's something that is relevant, and b) that's not privileged, either for crime fraud exemption or some other reason, and then likely convince a judge or special master that the privilege doesn't apply.”

This is because of a rule under Title 9 of the Department of Justice's U.S. Attorneys' Manual regarding obtaining evidence from an attorney. Maas, a former assistant U.S. Attorney, explained, “The Justice Department manual has pretty specific procedures. It allows for some variations, but essentially the U.S. Attorney Office's or Mueller's worst nightmare is that somebody has privileged information given to them and thereafter in some fashion it taints the investigation.”

Also at play in the investigative timeline are duties under the Brady doctrine, a pretrial discovery rule requiring prosecutors to reveal exculpatory information to defense. “From an investigative standpoint, they've got to keep track of all these different lanes to make sure they're following all the right rules to make sure they don't impair their ability to prosecute someone if they think a crime has been committed,” Redgrave said.

He added, “If you didn't do the right forensic collection, didn't have the right chain of custody, all those seemingly simple things,” issues can arise down the road.