Story highlights Ri Jong Chol, the only N Korean arrested in connection with the case, has been released

Kim Jong Nam was killed February 13 at an airport in Kuala Lumpur

Kuala Lumpur, Malaysia (CNN) Ri Jong Chol, the North Korean man held in connection with the death of Kim Jong Nam, left Sepang Police district headquarters in Malaysia Friday under heavy police escort.

Ri is being handed over to immigration officials and transported to Kuala Lumpur international airport, Malaysia's National Police Deputy Inspector-General Noor Rashid Ibrahim told CNN.

The only North Korean arrested in connection with the case, Ri appeared to be wearing a bullet-proof vest when he was escorted out of the building by half a dozen police, some of whom covered their faces with balaclavas and carried automatic weapons.

North Korean national Ri Jong Chol is escorted with a heavy police presence as he leaves the Sepang police headquaters in Sepang on March 3, 2017.

Police don't have sufficient evidence to charge Ri Jong Chol, Malaysian Attorney General Mohamed Apandi Ali told CNN Thursday. Ali said he'll be deported to North Korea after his release.

Kim, the older half-brother of North Korean leader Kim Jong Un, was killed February 13 before he was supposed to board a flight to the Chinese-controlled territory of Macau.