NEW YORK, NEW YORK - OCTOBER 17: Former Donald Trump presidential campaign manager Paul Manafort looks on during Game Four of the American League Championship Series at Yankee Stadium on October 17, 2017 in the Bronx borough of New York City. (Photo by Elsa/Getty Images)
PHOTO: Elsa/Getty Images
NEW YORK, NEW YORK - OCTOBER 17: Former Donald Trump presidential campaign manager Paul Manafort looks on during Game Four of the American League Championship Series at Yankee Stadium on October 17, 2017 in the Bronx borough of New York City. (Photo by Elsa/Getty Images)
Now playing
02:39
Judge rejects Manafort's effort to dismiss case
Paul Manafort attorney statement vpx _00003417.jpg
PHOTO: CNN
Paul Manafort attorney statement vpx _00003417.jpg
Now playing
00:35
Attorney explains why Manafort pleaded guilty
PHOTO: Getty Images
Now playing
01:05
Remind me ... who is Paul Manafort?
CLEVELAND, OH - JULY 17:  Paul Manafort, campaign manager for Republican presidential candidate Donald Trump, is interviewed on the floor of the Republican National Convention at the Quicken Loans Arena  July 17, 2016 in Cleveland, Ohio. The Republican National Convention begins tomorrow.  (Photo by Win McNamee/Getty Images)
PHOTO: Win McNamee/Getty Images
CLEVELAND, OH - JULY 17: Paul Manafort, campaign manager for Republican presidential candidate Donald Trump, is interviewed on the floor of the Republican National Convention at the Quicken Loans Arena July 17, 2016 in Cleveland, Ohio. The Republican National Convention begins tomorrow. (Photo by Win McNamee/Getty Images)
Now playing
01:21
Mueller team: Manafort agrees to plead guilty
Paul Manafort, advisor to Donald Trump, is seen on the floor of the Quicken Loans Arena at the Republican National Convention in Cleveland, Ohio, July 19, 2016.
PHOTO: Tom Williams/CQ-Roll Call,Inc.
Paul Manafort, advisor to Donald Trump, is seen on the floor of the Quicken Loans Arena at the Republican National Convention in Cleveland, Ohio, July 19, 2016.
Now playing
01:25
Manafort's journey to center of Mueller's investigation
Former Trump campaign chairman Paul Manafort leaves Federal Court on December 11, 2017 in Washington, DC.
In October, Trump's one-time campaign chairman Paul Manafort and his deputy Rick Gates were arrested on money laundering and tax-related charges. Brendan Smialowski/AFP/Getty Images
PHOTO: Brendan Smialowski/AFP/Getty Images
Former Trump campaign chairman Paul Manafort leaves Federal Court on December 11, 2017 in Washington, DC. In October, Trump's one-time campaign chairman Paul Manafort and his deputy Rick Gates were arrested on money laundering and tax-related charges. Brendan Smialowski/AFP/Getty Images
Now playing
02:34
Manafort found guilty on 8 counts
Juror Manafort
PHOTO: FOX NEWS
Juror Manafort
Now playing
01:14
Juror from Paul Manafort trial speaks out
PHOTO: CNN Illustration/Getty Images
Now playing
01:53
What the Manafort and Cohen case results mean
juror Paula Duncan
PHOTO: CNN
juror Paula Duncan
Now playing
01:34
Juror: Manafort pardon would be grave mistake
President Trump departs the White House South Lawn.
PHOTO: CNN
President Trump departs the White House South Lawn.
Now playing
01:43
Trump: Manafort trial is very sad
Paul Manafort arrives for a hearing at US District Court on June 15, 2018 in Washington, DC. (Photo by Brendan SMIALOWSKI / AFP)        (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images)
PHOTO: BRENDAN SMIALOWSKI/AFP/AFP/Getty Images
Paul Manafort arrives for a hearing at US District Court on June 15, 2018 in Washington, DC. (Photo by Brendan SMIALOWSKI / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images)
Now playing
02:12
Prosecutors: Manafort case all about 'lies'
PHOTO: Bill Hennessy
Now playing
01:16
Prosecution rests their case in Manafort trial
PHOTO: Bill Hennessy
Now playing
02:23
Banker testifies after unexplained recess
PHOTO: Bill Hennessy
Now playing
00:53
Day 9 of Manafort trial begins with mystery
PHOTO: Bill Hennessy
Now playing
02:23
Judge: 'Probably wrong' to scold prosecutors
PHOTO: Bill Hennessy
Now playing
02:57
Frustrated Manafort emailed Gates: WTF?
(CNN) —  

Federal Judge Amy Berman Jackson on Tuesday rejected former Trump campaign chairman Paul Manafort’s attempt to invalidate the criminal case against him in Washington.

Manafort had claimed special counsel Robert Mueller’s appointment order was too broad, and thus his investigation had overstepped its legal authority.

But Berman Jackson concluded for several reasons that Mueller’s investigation and prosecution of Manafort is legal – and that the special counsel still can maintain some independence while working within the Department of Justice.

Manafort has pleaded not guilty to charges related to his lobbying work for Ukrainian politicians dating back to a decade ago.

“It bears emphasizing at this stage that Manafort is presumed to be innocent of these charges, and it will be the prosecution’s burden to prove him guilty beyond a reasonable doubt. But the indictment will not be dismissed, and the matter will proceed to trial,” Berman Jackson wrote in her opinion Tuesday.

She added that it was appropriate for federal investigators to look into Manafort’s business connections in Russia and Ukraine while Mueller’s office investigated possible coordination between the Trump campaign and the Russian government.

“Who had connections to the Russian government? Who attended meetings on behalf of the campaign?” Berman Jackson wrote. “Given the combination of his prominence within the campaign and his ties to Ukrainian officials supported by and operating out of Russia, as well as to Russian oligarchs, Manafort was an obvious person of interest.”

“The Special Counsel would have been remiss to ignore such an obvious potential link between the Trump campaign and the Russian government,” she wrote later in the opinion.

Jason Maloni, a spokesman for Manafort, later responded to the ruling: “Paul Manafort maintains his innocence and looks forward to prevailing in this matter.”

Manafort is scheduled for trial in DC in September.

He faces a separate set of bank fraud and other financial charges in Virginia, for a trial set to begin in July. Manafort has asked a different federal judge there to dismiss his case on similar grounds. The Virginia federal judge, TS Ellis, has not yet ruled on the question. Ellis expressed his skepticism at a previous hearing that Mueller’s current investigation into Russian coordination during the 2016 campaign would connect to Manafort’s lobbying activities years before the Trump campaign existed.

Berman Jackson previously dismissed a civil lawsuit Manafort had attempted to use to undercut Mueller’s authority.