"Are you sitting down? Frankie is alive," a family friend told the elder Kerrigan, 81, before handing the phone to his 57-year-old son, whose name is Francis.
"Frank gets on the phone, says, 'Hi, Dad, how are you doing?' " the elder Kerrigan said on NBC's "Today" show.
Kerrigan's oldest child -- who is homeless and mentally ill -- had visited the home of a family friend, a pallbearer at the funeral.
According to the Kerrigan family and their attorney, the Orange County Coroner's office claimed the younger Kerrigan died on May 6. Officials told his father they identified him through his fingerprints, the family said.
Kerrigan told NBC that, at the time, that sealed it for him. "As soon as they said that it was by his fingerprints, that was the dagger in my heart," Kerrigan said.
But officials had wrongly identified the body of a man who was found dead outside a cellular store in Fountain Valley, California. The family's attorney said the identification was made with an old Department of Motor Vehicles photo.
"It feels like a miracle that my son is actually alive, but that does not take away the pain and grief we've gone through since this ordeal began," the elder Kerrigan said.
The younger Kerrigan's sister, Carole Meikel, 56, of Silverado, California, said she wants answers.
"This was just blatant disregard because he was homeless, just a throwaway," said Meikel.
'Procedures were cut short'
A family attorney, Matthew Easton, has filed notices of claims, a prelude to a lawsuit, against Orange County on behalf of the elder Kerrigan and Meikel.
Easton alleges the younger Kerrigan's civil rights were violated and that the family suffered from emotional distress.
The coroner failed to "follow proper protocols and precautions in the identification process" because Kerrigan was homeless, Easton said.
In a statement Monday, Easton said the family hopes to "help prevent incidents like this in the future and ensure that the homeless are treated with the dignity and humanity that all people deserve, both in life and death."
The family is also seeking a little more than $2 million in damages, which includes $20,768 in funeral and burial costs.
In an email, Easton said "that cemetery, which used to be a place of serenity and calm where the matriarch of the family is buried and where they thought they were interring their son and brother to be at peace with her, is now desecrated."
The Orange County Sheriff's Department is investigating the botched identification and has apologized to Kerrigan's family.
The Orange County Coroner's Office released a statement on Monday that said it has identified the man buried last month, who was mistakenly thought to be Frank Kerrigan, Jr. The statement said officials are trying to locate the man's family and are not releasing his name until they do so. The Coroner's office said the man's body will remain buried "until his family can be found or all efforts are exhausted."
The Coroner's office statement said officials have "worked diligently to rectify" the misidentification since first learning about it, but provided no details as to what led to the error, citing an ongoing internal investigation.
The Kerrigan family's attorney claims officials knew the real identity of the man who was buried weeks ago but failed to try to find the man's family until the story made national headlines.
Easton said the coroner's response "continues to evidence the lack of care and attention that this homeless decedent, and others like him, have received from the Coroner."
The Orange County Coroner's Office did not immediately respond to CNN's request for comment to clarify when the identity of the man was determined.
'There was blood and a dirty blanket'
The family's ordeal started when the elder Kerrigan received a note from the Riverside County Sheriff's Office telling him to call the Orange County Coroner's office about his son, according to a copy of the claim. That's when the family was told the younger Kerrigan had been found dead near the cellular phone store.
Kerrigan asked if he needed to come to the coroner's office to identify his son. He said he was told there was no need because they had his fingerprints and a positive identification.
He was told he couldn't claim the body until after an autopsy was performed, the claim said.
Kerrigan and Meikel went to the scene. She left a candle, flowers, a rosary from her daughter's kindergarten graduation and a framed photograph of her brother, with a note that said, "your family loves you."
"There was blood and a dirty blanket," she said. "It felt like something bad happened there."
Meikel wondered if her brother -- whose life unraveled after his mother's death -- had died violently. She had feared he would die homeless and hungry.
"I was horrified," she said.
The next morning, she said the called the Orange County Sheriff's Department. They assured her that her brother had died peacefully.
An autopsy found that Kerrigan died from an enlarged heart and fluid in his lungs, KABC reported
The family said they saw the body days before his funeral, and he was tough to recognize, the station reported.
About 50 people, hailing from cities such as Las Vegas and Ontario, Canada, attended a Mass at Holy Family Cathedral. One mourner drove 200 miles.
"There were all kinds of cars behind the hearse. He wasn't just a homeless guy; he was my brother. He was a real loved family member," Meikel said.
Pallbearers carried the body to its final resting place, next to the family matriarch, who Easton said died a decade ago.
Things didn't add up
But to Meikel and her father, some things didn't make sense.
"They told my father they identified him through fingerprints. They told me they had his identification but his wallet was empty," she said.
A bag they received wasn't the black attache case her brother carried. And authorities could not locate his belongings, which included a cherished watch and pin, she said.
Then came the phone call from the pallbearer on May 23.
On June 1, Easton said his office informed the coroner's office of their mistake. He said officials said they ran the existing fingerprints again and got a match. But they never exhumed the body buried in the next to Kerrigan's late wife.
Meikel said the family had to notify everyone at the funeral that her brother was alive.
Today, the younger Kerrigan is homeless by his own choice and stays in contact, his family said.
His disability payments ceased because he was labeled as deceased. Easton said the coroner's office is reaching out to Social Security.
Meikel said she is still grieving but relieved.
"It's a blessing, but it doesn't wipe away what happened," she said.