Trump has fought document subpoenas for 3 years. So why didn't the Manhattan DA just get a search warrant?

• The Manhattan DA's ex-investigations chief can't understand: why no search warrant on Donald Trump?
• Trump has successfully fought documents subpoenas for three years, until Thursday.

A former top prosecutor with the Manhattan District Attorney's Office says it is "remarkable" that former President Donald Trump has managed to keep his business files out of the hands of local investigators throughout three years of subpoenas and court battles.

Only on Thursday did a Manhattan judge order Trump to comply with a series of New York Attorney General civil subpoenas for the former president's testimony and personal business documents, many of which the AG believes he has kept at his headquarters in Trump Tower.

But with both the AG and the DA conducting parallel probes, why, wondered former Manhattan DA Investigations Chief Adam Kaufmann, hasn't the DA simply gone into Trump Tower with empty boxes and a search warrant?

Trump has repeatedly denied any wrongdoing.

Put another way, why rely on the more dainty, drawn-out process of civil subpoenas — AG Letitia James issued her first demand for Trump business documents in early 2019.

"This is remarkable," Kaufmann told Insider of the long battle for Trump's files.

"It suggests that after all this time, The Trump Organization has managed to evade disclosure of the very records that would point directly to the involvement and knowledge — or lack thereof — of Trump himself," he said.

"What I do not understand is this," added Kaufmann, a partner specializing in white-collar criminal defense at Lewis Baach Kaufmann Middlemiss.

"If this is true, and there are documents constituting evidence still with The Trump Organization, then why has the DA not gone after those documents in any fashion, or gone after the Trump Organization for not producing them?"

The Manhattan DA's office did not immediately respond to a request for comment.

Still, search warrants can be problematic.

"The pros are, obviously, you don't have to trust the company — you just take stuff," said Daniel R. Alonso, who as former chief assistant DA was second only to Cyrus Vance during his first term.

"A search warrant has the element of surprise," said Alonso, a partner at Buckley LLP.

"It's a fantastic tool when an investigation has been covert up until that moment."

The cons, he said, are that getting a search warrant "takes a ton of resources, and you can be challenged if you are wrong about probable cause or if you seize a document that's beyond the scope of the warrant."

Search warrants can work well when law enforcement wants to seize such physical evidence as guns, drugs, or money, says white-collar defense attorney John Moscow, who prosecuted complex financial crimes at the Manhattan DA's office.

"There are times you know something is there, you know where it is, and you go in and grab it before it moves," Moscow, told Insider.

But when investigators are looking for paper, subpoenaing whoever has that paper is typically the better route, he said.

That person is then the one who has to gather up the responsive documents — and they can then be asked to sit down and provide context for each page.

"If it's paperwork, as a prosecutor you need someone to sit down and walk you through that paperwork, and say what the documents are," said Moscow, who is senior counsel at Lewis Baach.

"Your chances of that are much better with a subpoena, and you can't do that with a search warrant."

Then there is the question of whether the documents James initially sought will still be produced now, three years later.

In court papers filed in January, James complained that Trump officials were not sufficiently helping a third-party document search firm that has been hired, under court order, to help gather all subpoenaed documents.

"Now, it's late in the game," said Alonso. "Without suggesting anything untoward, to me, if there was smoking gun physical documents it's less likely that they're still there" three years later.

Still, hiding or even destroying documents can come back to haunt a defendant.

First of all, it's illegal and punishable by a contempt of court charge.

"The state has stronger law on this than federal law," said Alonso. "The company or the individual can be held in contempt."

And destroying a document can backfire in a big way.

"[DC-based defense lawyer] Bob Bennett likes to say 'No document is as damaging as one that can be proven to have existed," Moscow said, "but which isn't produced."