SATELLITE PHOTOGRAPHY has become an invaluable tool in the cause of human rights. David Hawk and Amanda Mortwedt Oh of the Committee for Human Rights in North Korea used it to prepare a report providing unsettling details about a parallel set of prison camps in North Korea that exist along with the political camps exposed earlier. These are places with "gated high walls and barbed wire fences, guard towers, dormitories, and workshops or mines," further evidence that North Korea's leaders have carried out crimes against humanity.

Previously, a United Nations Commission of Inquiry reported in 2014 on a chain of penal camps in North Korea operated by the Ministry of State Security, or secret police. These political or concentration camps are hidden and extrajudicial, and people can be held incommunicado for life. Family members are held there also. The camps are used to "preemptively purge, punish, and remove from North Korean society" those whom the regime fears might challenge their rule or their ideology, Mr. Hawk says.

The new report fleshes out details of a second chain of punishment camps, run by the Ministry of People's Security, in which prisoners serve fixed terms and are not held incommunicado, and their families are not incarcerated. These camps hold those accused of regular crimes, such as murder, assault and theft, but Mr. Hawk points out they also hold prisoners accused of political "crimes" set by the state. They include taking part in unauthorized gatherings; criticizing the state or even expressing dissatisfaction privately; possessing "decadent" drawings, written materials, periodicals, music, movies or videos; and "foul, hostile, or superstitious activities." According to Mr. Hawk, the nation's criminal code has provisions that could get someone thrown into these camps for failing to follow state agency instructions, spreading rumors "that may lead to the distrust of the state or its agencies" and "not rightly selecting winning athletes for important competitions." In other words, pick the wrong team goalie, and you're off to jail.

Prisoners in this parallel gulag suffer the deprivations of the other concentration camps, including starvation, forced labor and brutal conditions that lead to large numbers of deaths. It is not known precisely how many prisoners the camps hold — satellite imagery shows them in almost every province — but the U.N. report had suggested 70,000 or more. Mr. Hawk says they have sometimes been called reeducation camps, but that is a terrible misnomer; what's going on is far more severe than just brainwashing sessions.

The Nazi concentration camps shocked the world. If such a horror is discovered today, shouldn't it prompt a response? Mr. Hawk has laid out the evidence of atrocity. So did the U.N. commission three years ago. North Korea is not only a testbed of nuclear weapons and missiles. It is also a black hole of human souls. That is another reason not to turn a blind eye to Kim Jong Un and his barbarous rule.