Being my first reflection on the novel, this is a good opportunity for me to mention how great it is. For starters, as a book, it is very interesting and suspenseful and nearly impossible to put down. It is also a translation from Russian and provides an interesting and accurate insight into the time and place as Dostoevsky himself was in a situation of poverty at the time of writing.
Finally, as an extra, somewhat rare, bonus, it is packed with philosophical ideas that will provide you with dozens of conversation topics and bring you to the brink of insanity more than once. One example of the casual presentation of a huge idea, as carelessly as if he were merely saying hello is the random outburst which ends a chapter: “'Man grows used to everything, the scoundrel!' He sank into thought. "And what if I am wrong?" he cried suddenly after a moment's thought. "What if man is not really a scoundrel, man in general, I mean, the whole race of mankind - then all the rest is prejudice, simply artificial terrors and there are no barriers and it"s all as it should be.'”
Now that that's over with, the point of this reflection; the moral dilemma of whether or not it can ever be right to take a life. The particular situation created by Fyodor Dostoevsky in Crime and Punishment is: “'On one side we have a stupid, senseless, worthless, spiteful, ailing, horrid old woman, not simply useless but doing actual mischief, who has not an idea what she is living for herself, and who will die in a day or two in any case … on the other side, fresh young lives thrown away for want of help and by thousands, on every side! A hundred thousand good deeds could be done and helped, on that old woman's money.'”
Hmm… well today I believe the murder itself is wrong, even if there were no consequences besides a transfer of wealth and the death of a tyrant (though this is an impossible situation), but that's just my view, and only today… so rather than thinking aloud and giving you my own reasoning (which is too hard to do without someone probing me with questions anyway) I'll just present some information from the novel for you to ponder this further on your own, and perhaps decide you have to buy the book.
Most importantly, I think you need to know what Dostoevsky tells us on the topic, and this is represented by what happens with the main character, because, after having his own belief confirmed by overhearing the above quote in a tavern, he goes through with the murder. But as one may suspect, murder is never simple, and he is walked in on by the old woman's kind sister who he is also forced to murder, then he has to endure terrible internal suffering as a result of the murders, ultimately turning himself in.
Another point from the book which may help you decide is given to the speaker of the previous quote by the man who he was discussing the idea of the murder with: “'You are talking and speechifying yourself away, but tell me, would you kill the old woman yourself?'” to which he had to reply: “'Of course not! I was only arguing the justice of it … It's nothing to do with me …'” and finally his idea is rendered completely invalid with “'But I think, if you would not do it yourself, there's no justice about it … Let us have another game.'”