Federal investigators are using an age-old tactic in their grand jury probe of former Honolulu Prosecuting Attorney Keith Kaneshiro.

They’re following the money.

Some of Kaneshiro’s top political donors have become central figures in the U.S. Justice Department’s ongoing criminal investigation into corruption and abuse of power within the city prosecutor’s office.

Chief among them are Honolulu-based real estate agent Donna Walden and engineering consultant Dennis Mitsunaga, whose firm Mitsunaga & Associates has previously been the subject of allegations of pay-to-play politics.

Most recently, Assistant U.S. Attorney Michael Wheat, the San Diego-based prosecutor spearheading the investigation, has called in several employees of Mitsunaga & Associates to testify before a federal grand jury.

At least one company executive, Arnold Koya, was booked into the Federal Detention Center in Honolulu after he refused to show up, according to a report from Hawaii News Now.

State campaign spending data shows Koya, like other Mitsunaga & Associates executives, has donated thousands of dollars to Kaneshiro’s political campaign to help him stay in office.

“Michael Wheat is a very skilled and diligent prosecutor so it makes sense to me that he would investigate the people who have given campaign contributions to a criminal defendant in one of his cases,” said Marc Wallenstein, a former assistant U.S. attorney who now works in private practice.

“If a criminal occupies an elected or appointed office and abuses his power you want to investigate the people who helped put him there, which includes campaign donors even though it doesn’t necessarily mean they committed a crime.”

Wheat is focused in particular on Kaneshiro’s involvement in the City and County of Honolulu’s $5.5 million purchase of an apartment complex from Walden shortly after she and her investors bought it for $4.5 million. Kaneshiro wanted to use the building as a “safe house” for victims of sex trafficking and domestic violence.

A grand jury witness who helped execute the deal told Civil Beat in 2017 that Kaneshiro advocated for purchasing the building from Walden and that Wheat took specific interest in the seemingly quick $1 million profit that came as a result.

Walden did not respond to Civil Beat’s recent request for comment, but in 2017 defended her involvement saying, “We did a good deed.”

Kaneshiro’s safe house was shut down in 2019 after a series of controversies, including complaints of civil rights abuses.

Wheat is also looking into Kaneshiro’s prosecution of Laurel Mau, a former Mitsunaga & Associates employee who had sued the company for sex and age discrimination.

After Mau filed her lawsuit, Kaneshiro’s office pursued criminal charges against her based on affidavits and witness statements prepared by Mitsunaga & Associates and its attorney Sherry Tanaka. No other outside law enforcement agencies, such as the Honolulu Police Department or the Hawaii Attorney General’s Office, were involved in vetting the case.

Instead, it was handled by one of Kaneshiro’s internal investigators, Vernon Branco, and two of his deputy prosecutors, Chasid Sapolu and Jake Delaplane, both of whom have come under scrutiny during Wheat’s ongoing criminal investigation.

Karen Nakasone, a state court judge, threw out Kaneshiro’s case against Mau in 2017, saying it was “highly unusual,” “irregular” and a “threat to the judicial process.”

Mitsunaga and Tanaka, who has been representing the company’s employees before the grand jury, did not respond to Civil Beat’s requests for an interview.

Kaneshiro additionally declined to comment about the ongoing criminal investigation when contacted by Civil Beat last week.

“I was advised by my attorney not to say anything,” Kaneshiro said. He declined to provide the name of his attorney.

Alexander Silvert is a former federal public defender who’s familiar with Wheat’s tactics.

Silvert represented Gerard Puana, who retired Honolulu police chief Louis Kealoha and his wife, Katherine, a former deputy city prosecutor under Kaneshiro, tried to frame for the theft of their mailbox.

Wheat successfully prosecuted the Kealohas and several others, including a number of HPD officers, who were involved in the conspiracy to set up Puana after Silvert and his investigators uncovered the scheme. Wheat also went after the Kealohas, and Katherine in particular, on a number of other charges related to bank fraud, identity theft and drug trafficking.

Silvert said Wheat appears to be investigating Kaneshiro the same way he would a white collar criminal.

“Al Capone didn’t get charged for murdering people, he got charged for tax evasion,” Silvert said. “Following the money and following possible improper campaign contributions is kind of a classic, old school FBI method.”

Whether Wheat can prove a quid pro quo is another question, Silvert said.

“Here there appear to be campaign contributions on the one hand and then very definitive acts on the other,” Silvert said. “This quid pro quo seems to have some meat to it.”

Kaneshiro was notified he was a target of the Justice Department’s criminal investigation in 2018 while still serving as the city’s top elected prosecutor. He eventually took a paid leave of absence after Hawaii Attorney General Clare Connors petitioned the state Supreme Court to have him suspended.

For the most part, Wheat’s investigation into Kaneshiro has remained out of public view. In 2019, much of the public focus was on the Kealoha trial and its subsequent fallout after the couple was convicted along with two of their police officer co-conspirators, Derek Hahn and Minh-Hung “Bobby” Nguyen.

The coronavirus pandemic further detracted from the investigation and complicated Wheat’s efforts in part because he and his team of prosecutors are based in San Diego and COVID-19 court restrictions temporarily shut down the grand jury proceedings.

That all changed once Wheat started bringing in employees of Mitsunaga & Associates to testify.

Together Walden, Mitsunaga and their affiliates, including family members and business partners, donated more than $50,000 to Kaneshiro’s campaign between 2010 and 2016, which accounts for more than 15% of his total itemized contributions in that time.

Walden was among Kaneshiro’s top campaign contributors, according to data from the Hawaii Campaign Spending Commission. She and her business partners, including her ex-husband Brian Sakamaki and Giampaolo “Paul” Boschetti, have donated at least $9,000 to Kaneshiro’s campaigns since 2012, including through two limited liability companies, LionKing II LLC and Microwave LLC.

Mitsunaga, too, was a major contributor to Kaneshiro’s campaigns between 2010 and 2016, records show. He and his family, including his wife, Chan, and daughter, Lois, gave more than $20,000 to Kaneshiro. Other executives of Mitsunaga & Associates gave thousands of dollars more.

Silvert said Wheat appears to be trying to get someone at Mitsunaga & Associates to start talking about the company’s relationship with Kaneshiro, but based on the actions of Koya and others it seems like he might not be getting the cooperation he desires.

“Everybody is playing hardball here and I know Mr. Wheat gets more energized when you play hardball,” Silvert said. “He takes it as a personal challenge so it may not be the right approach to try dampening the investigation into what’s happened here.”