Which Is More Wrong -MURDER or SUICIDE-

Recently, the incidents about suicide and murder happen frequently all over the world. Suicide is killing him/herself and murder is killing other people. I hear that Japan, my country, become second country in whicth there are many people who kill themselves. Furthermore, though the law prohibits people have guns and swords in Japan, the TV tells that gun's incidents are often happenning in japan!! Now, many people lose their lives in these ways. I've been thinking the reasons why these people want to kill people including themselves and which, killing themselves or other people, is more wrong thing. But I haven't find these answers yet. What do you think about this?