A suspected opium distributor whose wife and three children were slain in what authorities call a drug-related attack said Thursday he regrets whatever role his dealings played in their deaths.

"I regret everything," Brian Tzeo said in an exclusive interview with The Associated Press. "It's something I never should have gotten involved in. It's hard to live with this."

Tzeo declined to discuss any details of the drug dealing that investigators allege he was involved in. Lisa Saephan, 40, and the couple's three children — 20-year-old Melanie, 18-year-old Pauline and 4-year-old Cody — were found shot and stabbed to death last week in their home north of Conover in Catawba County, about 40 miles northwest of Charlotte.

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Catawba County Sheriff's Office Chief Deputy Coy Reid said investigators believe Chiew Chan Saevang, 37, of Schofield, Wisc., and his girlfriend, 40-year-old Yer Yang of Long View, had come to the home to take a recent opium shipment from Thailand.

Investigators believe Tzeo was working with Saevang and Yang in a drug operation where he would convert the opium to heroin, then Yang would take it to Wisconsin where Saevang would sell it.

Authorities said Saevang killed Yang and himself late Tuesday night after a short police chase in Utah.

Kelly O'Driscoll, a spokeswoman for U.S. District Court in Madison, Wisc., said Saevang had been living in Wisconsin since Dec. 1 with an aunt and uncle.

"He did not have a job," she said. "He was waiting for some sort of work permit so he could begin working."

Saevang was sentenced in 2005 in North Carolina to nearly four years in federal prison for conspiracy to possess with intent to distribute opium. He was paroled in October 2007.

Parole officers in Eau Claire, Wisc., last saw Saevang on March 9. He has not been authorized to leave the state, O'Driscoll said.

O'Driscoll said Saevang apparently left for North Carolina shortly after meeting with the Wisconsin parole agent at 4 p.m. on March 9 and he returned briefly to Wisconsin March 13, according to his family.

Tzeo was meeting with investigators Thursday on the drug investigation. He said he hoped they would allow him to travel to California, where he planned to bury his family.

"I hope they understand," he said. "I'm trying to be strong and hold up. But it is very difficult. I'm so lonely without my family. I miss my family."