How many murders before life means life?

BBC News reports:

A killer who beat an 89-year-old woman to death, 25 years after being jailed for life for another murder, has been told he will never leave prison.

Odd job man George Norman Johnson, 47, killed Florence May Habesch as she made him a cup of tea in Rhyl, Denbighshire.
...
The court heard Johnson and another man launched a "sustained and savage attack" with knives and a pair of scissors in 1986, killing a man in his own home for £3.

In October 1986 he admitted murder, and was jailed for life with a direction that he should serve at least 17 years.

He was released on 20 March, 2006, on the condition he took regular drugs and alcohol tests.

He was recalled in January 2007 after a positive test, but was released in December 2007.

By October 2010, he had admitted that he was taking drugs, and later admitted he was taking heroin daily and owed money to local drug dealers.

The BBC article doesn't say what crimes Johnson was convicted of before his first murder in 1986, but it's clear that he should never have been released. I find it absurd that he was "jailed for life with a direction that he should serve at least 17 years". Life should mean life. If it had, the life of Mrs Habesch would have been saved.

I'm sure some readers of this story will take it as evidence for the evils of drugs, but in my experience drugs don't turn good men bad. At worst, they remove the already-low inhibitions of already-disturbed individuals. In any case, the answer is to hold people fully to account for their actions. If you choose to get high, you must accept responsibility for the things you do in that state.

Instead, our perverted 'justice' system will continue to let a dangerous minority roam free to rob, rape, and kill, while needlessly criminalising the actions of countless decent people who use prohibited substances for self-medication or harmless recreation.