To kill is simply to put to death.
To murder a person is to put him to death intentionally.
Assassinate is to murder by surprise, design or secret assault.
1. They kill us for their sport.
2. The pilot reported two kills during the mission.
3. She was killed in the collision of three cars.
1. One murder makes a villain.
2. The mafia boss ordered his enemies murdered.
1. King James was assassinated in his place while he was enjoying the company of his queen.
2. He assassinated his enemy's character.
3. Anwar Sadat was assassinated because many people did not like his peace politics with Israel.