Muhammad commanded his followers to kill people who leave Islam:
Sahih al-Bukhari 6922- Allah’s Messenger said, “Whoever changes his Islamic religion, then kill him.
Therefore is shouldn't surprise when Muslims try to kill anyone when they leave Islam:
On a different note, I praise the Lord Jesus Christ that he has opened the eyes of another human being and has led him to the foot of the cross. I loved his testimony, it was very, very moving.
For more on the subject of death and apostasy in Islam, here's a video from my brother in Christ Jesus, David Wood: