Kerrigan, 82, couldn't believe what he was hearing.
Then came the May 23 phone call from Shinker.
Eleven days after laying his son to rest, Frank J. Kerrigan got a call from a friend.
Lt. Lane Lagaret of the Orange County Sheriff's Department declined to discuss details of the case when contacted by BuzzFeed News Saturday, citing the internal investigation and pending legal case against the department. Easton said it's because Frank is homeless, The Register reported.
Frank M. Kerrigan with his father Frank Kerrigan.
Frank Kerrigan is reflected in a photograph of his three children John, Carole and Frank.
"The department extends regrets to the family of Frank M. Kerrigan, 57, for any emotional stress caused as a result of this unfortunate incident".
His friend Bill Shinker told him: "Your son is alive", adding that he was standing on his patio.
"He said, 'Hi, Dad, ' " the father said.
The mix-up began on May 6 when a man was found dead behind a Verizon store in Fountain Valley.
The mix-up has bewildered the elder Kerrigan, who blames the Orange County Coroner's Office for the confusion.
It was a miraculous turn of events for the grief-stricken family, though now the question was how could such a mishap occur and who had the family actually come to bury? According to The Associated Press, the younger Frank is mentally ill and homeless.
The coroner's office told him that he didn't need to go down there to identify him, saying that fingerprints confirmed who he was.More news: Samsung Note 8 rumours swell ahead of September launch
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"When somebody tells me my son is dead, when they have fingerprints, I believe them", Mr Kerrigan said.
'If he wasn't identified by fingerprints I would been there in heartbeat'. She left a photo and rosary at the spot.
It was, she told the Register, "a pretty disturbing scene".
"He was not given the dignity and the due-diligence in the process that a normal citizen of Orange County would get", she said. She hoped to honor her brother.
At the funeral, Mr Kerrigan had looked at the man in the casket and stroked his hair.
But apparently he was so overcome by grief that he didn't notice the man in the casket wasn't his son.
'I didn't know what my dead son was going to look like, ' he said.
Still, all along there were red flags that the dead man wasn't Frank. For example, some of his prized personal possessions were missing such as his watch and favorite writing pen. On top of that, since Kerrigan was declared dead, Social Security and disability payments are being withheld, so now the family has to try to get those restored as well.
It was a handsome ceremony in a Catholic church, the family told the Register.
A funeral service was held for Frank Jr on May 12 and his "body" was buried in an Orange County cemetery. A stranger was now resting approximately 150 feet from the older Frank's buried wife.
Kerrigan's family plans to sue the department for failing to make an adequate effort to identify the body correctly, according to the Register.
When the fingerprints of the dead man were put into the computer, they did not match those of Frank M. Kerrigan.