The Consulate General of Japan in Honolulu warned Japanese tourists about visiting Kakaako’s popular murals after a Japanese couple was attacked midday Monday in a bathroom at Mother Waldron Neighborhood Park.

Homeless people who had been living in the park “intervened on behalf of the tourists and made very good witnesses,” HPD Deputy Chief John McCarthy told the Honolulu Star-Advertiser.

Honolulu patrol officers and investigators tracked down the lone suspect Friday at his Windward residence, said McCarthy, who declined to specify where the man lives. Police arrested the 20-year-old male suspect around noon on suspicion of second- and third-degree assault, McCarthy said.

He called the assaults “really unfortunate and shouldn’t happen to anyone. … It was totally unprovoked.”

Mother Waldron — bordered by Pohukaina, Halekauwila, Cooke and Keawe streets — has seen an influx of homeless people, who flocked there after being forced in sweeps from Kakaako Waterfront Park and other areas nearby. Monday’s attack occurred after the city announced it was shutting down Mother Waldron on Tuesday for “maintenance.” It’s scheduled to reopen July 6.

Mayor Kirk Caldwell said he remains concerned about the presence of chronically homeless people around the park.

“When I first heard the story, I was concerned that this was an issue related to our homeless population,” he said. “It’s easy to demonize the homeless,” Caldwell told the Star-Advertiser. “They’re an easy target. I thought it was initially perpetrated by a homeless person. It reminds me that I shouldn’t just jump to conclusions.”

McCarthy said HPD would increase police patrols in the area following Monday’s assaults.

“I’m not going to wait for a second time or give people second opportunities,” he said.

A warning posted in Japanese on the consulate’s website advised Japanese tourists and Japanese nationals living in Honolulu to be aware that they stand out in Kakaako while taking photos of themselves with Kakaako’s “wall art.”

The consulate said a couple looking to use a park bathroom Monday came upon a group of males injecting drugs. The consulate said the man and woman were both punched in the face and choked and were left with broken teeth.

But Deputy Chief McCarthy said the consulate’s account is inaccurate.

Only one suspect was involved, he said, and “we have no evidence of drug use tied into this. The suspect may have used drugs prior or may have been on drugs at the time, but there’s no indication of that. … He’ll be prosecuted to the full extent of the law, and I support that.”

“I don’t know about the male being choked,” McCarthy said. “Both were punched.”

The couple face $50,000 in medical costs, according to Jessica Rich, president of the Visitor Aloha Society of Hawaii.

A Honolulu police officer filled out a report for VASH that “says nothing about teeth,” Rich said. “That’s not to say it didn’t happen.”

The consulate said the couple returned to Japan the day after the assault with their 19-year-old daughter. Rich said HPD reported that they also were accompanied by their 21-year-old son.

Rich said VASH has offered to solicit donations to help the couple pay for their medical bills. “Their biggest concern is their hospital expense,” Rich said. “VASH does not pay hospital bills, but we are trying to do what we can to raise money.”

The consulate’s warning said the area is known for purse snatchings and vehicle break-ins. But McCarthy said there have been no reports of purse snatchings and that the number of vehicle break-ins is not unusual, although he did not provide data.

“We can’t find any purse snatchings there, period,” McCarthy said. “Car break-ins? It’s no worse than anyplace else.”

Before Monday’s attack the area in or around Mother Waldron had seen “a minor assault” 18 months ago, McCarthy said.

William Ammons, a member of the Kakaako/Ala Moana Neighborhood Board, called the warning by the Consulate General of Japan “pretty serious.”

”Public safety is the foremost concern of people who live anywhere, and especially for tourists,” Ammons said. “You don’t want people feeling unsafe when they come here. If it rises to the level of the Japanese Consulate warning people not to go to a park restroom, that’s of great concern. It’s not good. It’s bad public relations. This community is developing a new identity. You don’t want violence to be a part of it.”

One of the leaders of the Kakaako murals, Kamea Hadar, said he was appalled by the attack and that he hoped it would not deter visitors from enjoying the murals.

“I feel terribly for the victims, of course,” said Hadar, co-lead director of Pow! Wow! Worldwide, which has painted — and repainted — hundreds of murals in Kakaako since 2011. “I don’t want anyone to feel uncomfortable and feel scared of Kakaako. Hawaii is still one of the safest places on earth, and Honolulu is one of the safest cities on earth in all my travels.”