The camera focuses on a color photo of an immigrant Korean man with his baby son on his lap; both are dressed in hanboks. A young man’s voice is heard: “I always relished my idea of being the son. I was always so involved with my family’s life, that I lived my life for them.” Then, a black-and-white family photo appears, and the camera zooms in on the serious-faced girl with braids. “But it was different for Catherine because she came to America in about her teen years,” the voice says. “She wanted to rebel. She wanted to be the ‘all-American girl,’ and my father didn’t like that.”

The scene is taken from a new documentary that explores the cultural and generational rifts in an immigrant Korean American family. Tragically, this real-life tale also involves murder, manipulation and betrayal.

For the last two years, Illinois-based filmmaker Iris Shim has been working on “House of Suh,” a documentary exploring the circumstances that led siblings Catherine and Andrew Suh to plan and execute, respectively, the 1993 murder of Catherine’s boyfriend, Robert O’Dubaine. According to authorities, Catherine had convinced her younger brother, then 19, that O’Dubaine was the one who had brutally stabbed their mother to death in 1987 to get his hands on insurance money and that it was Andrew’s duty to avenge it. Police never arrested anyone in connection with the mother’s killing, though they suspected Catherine, who with O’Dubaine used the inheritance money to buy a nightclub and live extravagantly. O’Dubaine served as Catherine’s alibi.

The unfinished “House of Suh” focuses particularly on Andrew, the good son, the congenial boy, the well-liked high school student body president. He was enrolled at Providence College in Rhode Island on a full scholarship when he admitted to lying in wait in the garage of the Bucktown, Ill., home O’Dubaine shared with Catherine and planting two bullets in his victim’s head. He is currently serving an 80-year sentence at the Pontiac Correctional Facility in Illinois. His sister is serving a life term without parole 30 miles away. Andrew is eligible for parole in 2035.

Andrew had one “fatal flaw,” says the 25-year-old Shim. “He’s got this fatal flaw of loyalty, which is why he is where he is.”

Her documentary is not about how this “Korean kid killed this guy,” she explains, “but about how someone could get to the point to kill another human being.”

Shim has a unique lense into Andrew’s life: she considers the 33-year-old inmate a close friend of six years.

After his conviction in 1995, Andrew wrote four- and five-page letters to Korean newspapers and churches, warning other young Korean Americans against the mistakes he had made. The letters won Andrew a network of supporters at a Chicago church he once attended, the same church where Shim served as the president of her youth group. She was a senior in high school when a church friend was so moved by one of Andrew’s letters that she started writing to him. Shim, then 18, decided to accompany this friend on a prison visit.