Police say surveillance cameras show Byun, of Flushing, leaving the bakery distribution warehouse on 55th Avenue where she works at about 4 a.m. Cameras did not capture her getting into her blue Honda Civic.
Her body was found in the trunk of her car, parked about two miles away, on Monday. She was wearing the same clothes she had been wearing when last seen on surveillance cameras, according to law enforcement sources.
Byun's ex-husband, Jae-yun Cha, told NBC 4 New York she worked the overnight shift as a cook at the bakery distribution center and that she had only gone back to work about three years ago, to help earn money to provide a better life for their two daughters, ages 15 and 14, and their 7-year-old son.
The college sweethearts met in Korea while studying architecture and moved to Louisiana in 1999, three years after they got married, Cha said. After another three years, they moved to New York City.
Though they divorced a year ago, Cha said he and Byun were about to remarry -- and now he has to support their three children on his own, he said. He said he hasn't told his children their mother is dead.
"As a Christian we have to forgive, but I can't," Cha said, referring to whoever killed Byun.