WATCH: FOX19 NOW one-on-one with Mayor John Cranley

WATCH: FOX19 NOW one-on-one with Mayor John Cranley

CINCINNATI, OH (FOX19) - Mayor John Cranley apologized to police leaders after his office mistakenly named a day for the man who killed Cincinnati police officer Sonny Kim.

Cranley went into crisis mode and granted FOX19 NOW's Tricia Macke an exclusive interview to discuss how this could have happened and how he's been sick ever since.

"I was in Columbia Tusculum talking to voters and i got a text that there was a problem and I immediately found out that this terrible thing had happened," he said. "When I first heard about it I couldn't believe it... I felt like I was having a heart attack."

[Mayor's office mistakenly honors Cincinnati cop killer]

On Thursday night, Cranley was just told his office approved a proclamation declaring "Tre Day" in honor of Trepierre Hummons, the man who shot and killed Sonny Kim, the 27-year veteran of the Cincinnati Police Department.

"As you know I helped eulogize Sonny Kim. It happened during my tenure and I got to know his family after the murder, and that this could have happened was extremely distressing," he said.

Cranley said he made three quick phone calls to the widow of Sonny Kim, Sonny's former partner, and the head of the FOP Dan Hils.

"He knew right away that this was unintentional. The hardest part was talking to Mrs. Kim and Sonny's partner, and I just regret that it caused them any harm... but as I said today, it was unintentional," he said. "They accepted my apology and said accidents happen, so I was very grateful for that."

Cranley then held a news conference with a tearful apology for what he said was an honest mistake by a staffer in his office.

"Reality is, if I shed a few tears over the last two days, she shed as many if not more and feels horrible as I do, and forgiveness has been offered to me," he said.

Cranley said the proclamation would never have been intentionally approved.

"We would have never issued this proclamation for the man who murdered Sonny Kim," he said. "We formally retracted the proclamation... we sent a letter to Trepierre's dad and said it was issued in error and that we would never issue a proclamation for someone who murdered Sonny Kim."

The mayor said he takes full responsibility for the mistake.

"Obviously we failed," he said. "I take total responsibility. It cam in, the people that deal with it didn't notice. The name was not spelled out and they thought they were responding to someone asking for a proclamation for awareness of a mental health issue. So the people involved didn't realize who was involved, but obviously that's not good enough and we are making sure it never happens again."

Following the incident on Thursday, Cranley said he made several more apologies on Friday.

"Then today, I made my way around the police officers at the memorial and shook a lot of hands and expressed my personal apologies... and got a lot of hugs and it's a real testament of forgiveness," he said.

Cranley said changes will be made to how proclamations are issued.

"Obviously we are going to have the greatest security protocols imaginable for any proclamation that goes out now, and we're going to have different people reviewing them and running a lot more traps," he said.

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