Trustworthy !!! Nobody in royal family could do so apart from Dipendra. It's not like killing harke or shyame inside their hut, even though it deals with great risks. It's about killing a king inside his Palace in the vigilance of his army. No outsiders could do so. King and CP are the only ones permitted to carry arms inside the palace. At what basis Gyanendra and Paras could execute such a cumbersome task? Did all the officers of RNA back brother of king and not the king? Remember, Kot massacre was a clash in army when Gagan Singh was killed. I do not think it's a consequnce of a conspiracy, if it was it would have leaked. It is more a result of whim. Most importantly, if it was Gyanendra's strategm then he would not do it in such a naive way that everybody could point finger on him. If he wanted to kill all the members of Birendra why he took Nirajan to Chitwan with him ? Coz taking him to chitwan coould foil the plot. 

षड्यन्त्रपूर्ण हत्या गर्ने योजना बनाउँदा र एउटा राजालाई आफ्ना आफन्तसामु मार्न खोज्दा देखिने असङ्ख्य भेरिएबल्स् (नियन्त्रण भन्दा बाहिरका विभिन्न सम्भावनाहरू)का जोखिम मोलेर कसैले त्यस्तो हत्याकाण्ड रच्थ्यो होला! फेरि अरू पनि मर्ने सम्भावना हुँदाहुँदै सपरिवार उपस्थित भोजको बीच अरू कसैलाई लगाएर दाइको हत्या गर्न लगाउनु मूर्ख्याईं हुँदैनथ्यो? ती अन्य षड्यन्त्रकारीले कुनै बेला आफ्नो सहभागिताबारे बक्लान् भन्ने सम्भावना पनि हेर्नुपर्‍यो। ईर्ष्या, लोभ र पापपूर्ण कार्य गरेको भनिएका ज्ञानेन्द्रको मस्तिष्कमा जो-कोहीले आफैंलाई राखेर हेरून् र प्रश्न गरून्- यो सब पत्यार लाग्ने कुरा हो? ...

These are notable points. Thanks Shantipriya for the post.