A Grammy-nominated music producer has been missing since Sunday after making two mysterious and desperate phone calls.
Christian Julian Irwin, 48, of the Topanga area of Los Angeles, placed two frantic phone calls to a childhood friend and fellow producer Fortunato Procopio around 3:45 a.m. on Sunday.
Irwin told Procopio he was being chased by people who he believed might kill him. He also said they had dogs with them.
"It's terrifying to all of us," Irwin's sister, Sharon Riolo, told "Good Morning America." "We know Chris well enough that if he says he's being pursued or is in danger, then this, in fact, is true."
Earlier this week, Procopio said Irwin was unwittingly drawn into a Nigerian Internet scam and had been threatened by a con artist. Deputy Luis Castro, a Los Angeles sheriff's spokesman, declined to comment on the possible Internet scam.
Riolo, however, has said Irwin got scared when he received a check for $50,000 in the mail from a group of Nigerians, according to The Associated Press. Riolo told "GMA" she could not comment further in light of the ongoing investigation.
"We're considering the worst at this point because he hasn't been heard from," said sheriff's Capt. Ray Peavy. "Unfortunately, it could very well be a homicide."
Irwin has worked with musicians David Bowie, David Crosby, Art Garfunkel, Carly Simon and De La Soul. He is 6-foot-2, 190 pounds with graying brown hair and blue eyes. He is believed to have been wearing a red and blue shirt and blue jeans.
Family members say he's a physically imposing man who doesn't scare easily.
"He's not a shrinking violet," Riolo said. "Chris is a very stable, gentle, kind person … Nothing was out of the ordinary. This is why it's to terrifying so all of us."
Riolo added that Irwin is a born-again Christian who has never been in trouble.
The only physical evidence uncovered has been a pair of Irwin's glasses, found down the hill behind his house.
"As of last night, they hadn't found anything or any clues that they shared with us," Riolo's husband, John, said. "They did say they would repeat a particular area of the canyon that was of particular interest to them at daybreak."
Family and friends remain hopeful.
"We're doing a lot of praying," Sharon Riolo said. "We're asking everyone else to pray."