The man who stabbed and killed a British member of parliament last fall has been sentenced to life in prison.

Ali Harbi Ali, 26, who was inspired by the Islamic State terrorist group, attacked Conservative Party member David Amess, 69, at a church event last October, killing him. Ali said the attack was revenge for Amess’ support of airstrikes in Syria.

During the trial, prosecutors called Ali a “committed, fanatical, radicalized Islamist terrorist.” Ali reportedly told detectives he’d been planning to kill a parliamentarian for years.

The jury took just 18 minutes to reach the conviction.

“It’s clear that the man who begins a life sentence today is a cold, calculated and dangerous individual,” Metropolitan Police Assistant Commissioner Matt Jukes said in a statement outside court following the sentencing.

Amess’ family gave a brief statement after the sentencing.

“Our amazing husband and father has been taken from us in an appalling and violent manner. Nothing will ever compensate for that,” they said. “We will struggle through each day for the rest of our lives. Our last thought before sleep will be of David. We will forever shed tears for the man we have lost. We shall never get over this tragedy.”

Some information in this report comes from Reuters.