The mysterious death of South Korean pastor Patrick Kim in China is being blamed on North Korea.

“On a Sunday evening in August, a middle-aged South Korean pastor collapsed suddenly near a taxi stand in Dandong, a Chinese city on the Yalu River overlooking North Korea,” reports Barbara Demick in the Los Angeles Times.

Kim, declared dead on arrival at a local hospital, had a discolored complexion, spots on his fingers and limbs, flecks of foam on his mouth. He was a human rights activist who secretly helped North Koreans escape into China.

“His family and South Korean diplomats believe he was killed by North Korean agents in retaliation,” writes Demick. “The weapon of choice: most likely a poisoned needle.”

“We are assuming there was a murder perpetrated. Although the evidence is circumstantial, it points strongly to North Korea,” retired South Korean intelligence officer Lee Dong-bak told the Times. “The poison needle has been in use by North Korean special operations for a long time.”

Kim was one of a number of evangelical Christians who not only smuggle defectors out of China but also send Bibles across the border. In mid-September, South Korean intelligence arrested a North Korean defector on charges that he had planned a similar attack in Seoul.

“The target in that case was Park Sung-hak, a human rights activist who has launched balloons into North Korea carrying anti-regime leaflets,” reported Demick. “The intended weapon again was reportedly a poisoned needle.”