So for the rest of his life he never has to worry about where his next meal is coming from or how he can find a warm bed. Meanwhile a family mourns for the daughter they will never see again.
Yeah life without parole is just one big vacation. Besides the free room and board, you never have to buy a car, sunscreen, health insurance, etc. You have a readymade social group and an ordered life run by pleasant prison guards who cater to your every wish. Not a care in the world for the rest of your life in a gilded cage.
I bet that was why he killed her.