The Wall Street Journal is asking for answers from the Phoenix Police Department after one of its Black reporters was handcuffed and detained shortly after conducting interviews outside of a Chase Bank. The department said it has launched an internal investigation into the incident and the city's mayor has apologized to the reporter.

The incident between reporter Dion Rabouin and the Phoenix police officer took place in November, but became public more recently after Phoenix TV station ABC15 reported on the incident.

"We're deeply concerned that Wall Street Journal reporter Dion Rabouin was detained, handcuffed and placed in the back of a police vehicle while reporting," a Journal spokesperson told NPR in a statement. "No journalist should ever be detained simply for exercising their First Amendment rights."

On Nov. 23, Rabouin, who is a finance reporter with the Journal based in New York, was detained in a Phoenix police car after conducting interviews about savings accounts outside a Chase Bank. Rabouin was in street clothes because he did not want people to believe he was trying to sell them something, ABC15 reported.

As Rabouin was standing outside on a sidewalk, he told ABC15, two employees asked him what he was doing — and then walked back inside the building. Rabouin said he was unaware the sidewalk in front of the bank was private property and that the bank's employees did not ask him to leave.

Shortly after that, a Phoenix police officer arrived on the scene.

"I saw a police car pull up. And the officer came out, walked into the branch, after about five minutes came out, and talked to me," Rabouin told ABC15 in a recent interview. "He asked me what I was doing. I identified myself. I said, 'I'm Dion Rabouin. I'm a reporter for The Wall Street Journal. I'm working on a story. I told the people in the branch what was going on.' And he said, 'Well you can't do that.' "

The officer, later identified as Caleb Zimmerman, accused Rabouin of trespassing on the property and later took him into custody, according to a police report.

In video captured by a bystander shows Zimmerman handcuffing Rabouin and placing him in the back of a police car. The video shows Rabouin repeatedly identifying himself to Zimmerman as a reporter for the Journal, but despite Rabouin's numerous attempts to identify himself, Zimmerman did not respond.

The bystander recording the video was also threatened with arrest by Zimmerman. After around 15 minutes when other officers arrived on the scene, Rabouin was released and allowed to leave the property.

In a statement to NPR, a representative for Chase Bank said the bank apologized to Rabouin. The representative did not go into any further details regarding the incident and what lead up to Rabouin's detainment.

In a Dec. 7 letter to Phoenix Police Department Interim Chief Michael Sullivan, Journal Editor-in-Chief Matt Murray described Zimmerman's actions during the incident as "offensive to civil liberties."

Murray demanded to know what steps will be taken by Phoenix police to ensure that neither Rabouin nor any other journalist is "again subjected to such conduct."

The Phoenix Police Department told NPR that it received the letter from the Journal expressing concerns regarding the incident.

"This letter was shared with our Professional [Standards] Bureau for review and they are conducting an administrative investigation. Once the administrative investigation is complete, it will be made available as part of a public records request," a department spokesperson said.

Rabouin declined to speak to NPR for an interview following the incident but said in a tweet Thursday: "I don't have much more to say about the situation with Phoenix PD" beyond the details in the ABC 15 report. "Thanks to everyone who has reached out to offer support. We're hoping to hear back from the chief or someone at the department soon."

Following his arrest, Phoenix Mayor Kate Gallego personally apologized to Rabouin, saying in an email obtained by NPR that she only became aware of the incident last week through news reports.

In a statement sent to NPR, Gallego calls the treatment of Rabouin "unacceptable" and said it does not meet her expectations for the Phoenix Police Department.

"I believe firmly in the first amendment rights of journalists. Chief Sullivan is completing his internal review of the decision-making involved in this case. I look forward to receiving swift answers and to seeing swift action," Gallego said.

The Committee to Protect Journalists, a nonprofit organization advocating and defending the rights of journalists, released a statement condemning the incident and calling for a thorough investigation into Rabouin's treatment during his detainment.

"We are deeply concerned by the Phoenix Police Department's treatment of Wall Street Journal reporter Dion Rabouin. Detaining and handcuffing a journalist—who was gathering news in a public place—is a flagrant violation of his First Amendment rights," said CPJ U.S. and Canada Program Coordinator Katherine Jacobsen.