It's savage, but, the crime was savage, yes? Life sentences are very rare, but we haven't had anything like the Boston Marathon, or other massacres, in Sweden. The closest to such a heinous crime, was the 2011 attacks, not in Sweden, but Norway. Anders Breivik, the lone terrorist, who killed 77 people, was sentenced to 21 years in prison. That is the maximum sentence, for Norway. By law, an incarceration can be extended, as long as the offender is still deemed a danger to society. It is expected that his sentence will be extended, and he will spend the remainder of his life in prison.
I'm not in favour, of very severe punishments, that offer no hope at all. Especially, if the offender is young. This crime, it's complex, as it wasn't one murder, but so many. He and his brother caused irrevocable harm to many survivors, from the bombing, also. Loss of limbs, terrible wounds. I understand, wanting to give him, the maximum possible sentence. I don't agree, with death penalty, being an option. I don't find it unconscionable, to sentence him to life imprisonment, for these exceptionally heinous crimes.