PS: seems I should spell it out.
The suspect first came to Seoul in 2001 using a false passport, but was deported in June 2003 by the Immigration Service, according to authorities.
However, he returned within two months, using a new name and passport, with his wife, two sons and four daughters.
a. Getting a new name and passport in less than two months presumably needs official collusion.
b. It should be noted that post-2001 the US really got its tentacles into the Pakistani entry/exit control systems. If you google around, you may find out about that. To be able to do what this suspect did without raising alarms -- my guess again is that the man needed official Pakistani help.
c. I doubt that the suspect is a recent recruit to the Taliban (really, ISI). They were putting an asset in place in 2001 - in South Korea of all places - a sign of long-term thinking. Such an asset could serve many purposes - an attack on US personnel or an attack to oblige North Korea in return for their help with missiles.
PPS: PISCES - as I remember, the system was installed by the US.