JK-series assassin droids were assassin droids designed with a folding body similar to that of a B1-series battle droid. They are believed to be manufactured by the Loronar Corporation during the New Republic Era. They could fold themselves into a tight ball and be placed in various droid frames, such as astromech, power droids, and medical droids with their assassination functions concealed.
It is believed the Loronar Corporation, concerned with the rise of the New Jedi Order along with a new government, began construction on the JK-series as a way to protect their investments if the new Jedi became a threat.
JK-05 was the first functional prototype built off the schematics of the old HK-series assassin droid. Stripping the design of its protocol droid exterior, they were able to create a leaner, more agile fighter. Combining some design concepts from B1-series battle droids and Demolition droids, they designed JK-05 with a collapsable, folding body that allowed it to be placed inside of a false droid frame. This allowed JK-05 and all subsequent versions to move freely throughout the galaxy to track and corner their targets.
The series was discontinued when the aggressive independent streak common with its HK-series predecessor manifested and the droids revolted against their 'meatbag' oppressors.
The JK-series was designed primarily to fight force-sensitive targets. Equipped with a variety of sensors to assist the droid in combating Jedi, it showed remarkable ability to counter typical Jedi maneuvers such as Force Push and Force Pull. Its limbs, free from the heavy plating of the HK-series, were quite flexible and gave the droid a range of motion that made its movements difficult to predict. Also, with the elimination of the protocol droid disguise, the JK-units had an upgraded, compact head with a single optical sensor. This photoreceptor upgrade allowed for better targeting and gave the JK-units a wider range of vision.
The JK-units were trained in the use of a blaster but relied heavily on their hand-to-hand combat programming, usually overloading hidden power sockets in their palms to add an extra punch to their blows. They received programming in lightsaber combat as well mainly to learn counters, though there were rumors of JK-units engaged in saber duels with Jedi. In addition to the combat programming, the JK-series housed a modest internal weapons system which could be fitted with interchangeable armaments ranging from gas emitters to micro-thermal missiles.
The JK-series was extremely aggressive. It retained much of its predecessors arrogance and disdain towards flesh based life-forms. A few individuals have been known to associate and work with JK-units, but their relationship tends to survive only for as long as it's convenient for the JK-unit.