An Orange County Sheriff's Department spokesman told ABC News that the agency was contacted by the Chicago Police Department after a sheriff's lieutenant, speaking at a Monday news conference, described the pilot as a former officer.
It was not immediately clear why the man, identified as 75-year-old Antonio Pastini, was in possession of the fake credentials. According to authorities, his other identification details and his Federal Aviation Administration pilot's license are still believed to be authentic.
Chicago authorities said the badge number found in the wreckage resulted in an item that had been reported lost in 1978.
Dashcam video: Plane bursts into flames midair before Yorba Linda crash
Pastini's daughter, who lives in Torrance, declined to comment on that aspect of the investigation, saying those details should come flesh out the truth.
"When I got the call that it was my father, I was just numb," Julia Ackley said. "I've been in his planes since I was a baby. We were just in his plane last month."
She said her father was a restaurant owner and experienced pilot who lived in Nevada. He flew into Fullerton Airport at least twice a month to spend weekends with her and his granddaughter. She said he was on his way home on Super Bowl Sunday after one of those family visits.
"He was a loving husband, loving father, loving grandfather and great grandfather," she said.
Ackley said her father changed his name to Antonio Pastini years ago, but isn't sure why. His birth name was Jordan Albert Isaacson.
She added that she is grieving for and right alongside the families of those who were killed inside the home.
As of Tuesday morning, the coroner was still in the process of identifying the four badly burned victims -- two men and two women -- who were killed in a home that was struck by the plane's debris. Their conditions require additional measures -- including DNA -- to reach official identifications.
A close friend of the deceased said the family had gathered for their annual Super Bowl party when the deadly incident occurred.
The small plane ascended to about 7,800 feet before it crashed about 10 minutes after taking off from the Fullerton Municipal Airport, National Transportation Safety Board investigator Maja Smith said. Its wrecked fuselage ended up in a residential backyard.
Shawn Winch, who lives near the two-story home that erupted in an inferno, said the plummeting aircraft "sounded like a missile coming at my house."
"I got over there and the house was just engulfed in flames," he said. "Stuff was blowing up in the garage and everything else. It was horrible."
The mayor of Yorba Linda will be hosting a candlelight vigil for the victims at Glenknoll Elementary School on Thursday at 7:30 p.m.