0
I kill ... I wound ... I will make mine arrows drunk with blood, and my sword shall devour flesh. Deuteronomy 32:39-42
The book of Joshua can be summed up with the following words: "So Joshua ... utterly destroyed all that breathed, as the Lord God of Israel commanded." (10:40) He did it to Jericho, Ai, Makkedah, Linah, Lachish, Gever, Eglon, Hebron, Debir, and 20 other cities. And he did it under God's command.
And God wasn't just an innocent bystander either. He was an active combatant. "The Lord God fought for Israel." (10:42) God slew them with a great slaughter and even "chased them along the way." Sometimes he "threw down great stones from heaven," and once he even stopped the sun from moving so that he and Joshua could get all their killing done in the daylight.
There are a couple other killings in Joshua that deserve mention: A family is burned and stoned to death (along with their animals) to punish the father for taking "the accursed thing", five kings are killed and hung on trees.
Here is a list of the killings in Joshua.