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.
The 46-year-old, who used the name Patrick Kim, had a discolored complexion, spots on his fingers and limbs, flecks of foam on his mouth. He was dead by the time he reached the hospital.
The pastor was a human rights activist who secretly helped people slip out of North Korea into China. And his family and South Korean diplomats believe he was killed by North Korean agents in retaliation. 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," said Lee Dong-bak, a retired official of the South Korean intelligence service and now an academic in Seoul. "The poison needle has been in use by North Korean special operations for a long time."
The accusations come as North Korean state-run media have threatened retaliation against South Korean activists trying to topple Kim Jong Il's regime. The activists, many of them evangelical Christians, not only smuggle out defectors but also send anti-Kim literature and Bibles across the border, sometimes by attaching them to balloons that float across the demilitarized zone between the two nations.
Patrick Kim's death, on Aug. 21, was the first of three attacks or plots that South Korean activists or officials believe were carried out by North Korea. A day later in another Chinese city, Yanji, a South Korean involved with missionary work was standing at an intersection when he felt a pinprick in his lower back. As he collapsed, he heard a man muttering behind him in Chinese, "Sorry, sorry." He survived the attack.
Then, in mid-September, South Korean intelligence announced that it had 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. The intended weapon again was reportedly a poisoned needle.
Wary of further inflaming tensions, the South Korean government has been cautious not to openly accuse North Korea of being behind the attacks. The South's Foreign Ministry said an autopsy on the pastor, conducted in China, did not find any trace of poison.
But a diplomat who spoke on condition of anonymity because of the sensitivity of the case said the South Korean government nonetheless believes Kim was probably murdered. The diplomat said South Korean officials recently interviewed the Chinese pathologist who conducted the autopsy and were told that the pathologist was able to screen only for the basics.
"If there was a special poison or pathogen, he would not be able to detect it," the diplomat said. "Seoul has made its decision about what happened, but perhaps for them to declare publicly what they think could require actions they are not prepared to take."
Fellow activists say they have no doubt Kim was murdered. And analysts say the three incidents, coming in rapid succession, point to an increasingly belligerent North Korean security apparatus willing to use any means to silence its critics, perhaps connected to the rise of Kim Jong Eun, youngest son and heir apparent of Kim Jong Il.
Young Howard, head of Open Radio for North Korea, which reports from Seoul on the reclusive communist regime, suggests that the attacks were part of an escalation in aggression toward South Korea. He cited a torpedo attack on a South Korean naval ship and the shelling of a South Korean island near disputed waters last year.
"North Korea has turned very hostile to South Korea, and this is part of the pattern we are seeing," he said. He said Kim Jong Eun may be trying to strengthen his standing with hard-liners in the military and intelligence communities.
The attacks send a strong message to Christian activists who are helping North Korean defectors in China. Patrick Kim, whose full Korean name has not been disclosed by his family, had been working surreptitiously with an underground railroad helping North Koreans escape through China.
He was also raising money for his cause in Korean churches in New York and Los Angeles, said activists including Do Hee-yun, head of the Seoul-based Citizens Coalition for Human Rights of Abductees and North Korean Refugees.
The day of his death, Kim had received a telephone call about 7 p.m. and ran out to meet somebody, according to a family friend who gave a detailed account of the events, on condition his name not be used. At 8:15 p.m., Kim called his wife to ask her to meet him downtown, saying he hadn't brought enough cash for a taxi home. When she arrived, her phone rang again. This time, a man whose voice she didn't recognize said her husband had collapsed and directed her to another location.
"When she arrived at the place, Pastor Kim already had lapsed into unconsciousness.… Kim's face was getting dark, and from the end of the fingers dark spots spread into the body," the family friend, a South Korean clergyman, said in an email.
At the hospital, doctors, nurses and police suggested that Kim had been poisoned, probably with a needle, the friend wrote. After the autopsy could not detect poison, the case was not pursued because an investigation would have meant Chinese police poking around the missionary networks operating within China.
In China, it is illegal to help North Korean defectors or to engage in missionary activities. But the 800-mile stretch of border with the North is crawling with underground churches, many of them funded by South Koreans or Korean Americans. It is also a listening post for intelligence agencies and journalists trying to understand the secretive regime.
The man attacked in Yanji, a 59-year-old South Korean academic and evangelical Christian who had been living in China for a decade, also acted as a missionary and helped defectors, according to a businessman from the region who knew him.
He survived after several days in the hospital and has since left China, according to another Korean working in the region. Nobody has been arrested in either attack in China.
In South Korea, authorities announced Sept. 15 that they had arrested a North Korean defector on charges of plotting a similar murder. His target was fellow defector Park Sung-hak, head of Fighters for Free North Korea, which floats leaflets, DVDs and U.S. dollar bills into North Korea.
Park told the South Korean newspaper Joongang Ilbo that he'd been planning to meet the defector, a man with the surname Ahn whom he had met previously, at a Seoul subway station Sept. 3, but that the National Intelligence Service warned him not to go.
Military analyst Park Syung-je said Ahn had a background in the North Korean special forces and gave frequent lectures about North Korea after he defected in 1996.
Christian activists say a number of their colleagues have died mysteriously or disappeared, often while working in China.
In one of the most famous cases, in 2000, Kim Dong Shik, a missionary who was a permanent U.S. resident, was grabbed as he was coming out of a restaurant in Yanji, forced into a car and driven to North Korea. His wife, who lives in Skokie, Ill., said he is believed to have died in a North Korean prison.
Jung-yoon Choi of The Times' Seoul bureau contributed to this report.