Re: I feel sorry for the defence lawyer...
Defence lawyer serves a few purposes, regardless of the defendant's guilt/culpability:
1) Present the defendant's version of events;
2) Advise the defendant of their rights under law;
3) Inform the court of any mitigating circumstances, such as self-defence, duress, mental illness/instability;
4) Cross-examine any witnesses;
5) Keep the prosecution in check regarding points of law, questionable evidence, inadmissable testimonies etc.
6) Try to secure a sentence which is balanced within the law, rather than excessive punishment.
Probably several other points I've missed but you get the idea.
So even if the defendant did it and it's plainly obvious he/she did it, they're still entitled to a defence lawyer.