Iowa foster care officials say violence between children in foster care is very rare. The Department of Human Services is investigating the case of a 5-year-old foster boy who was killed this weekend, allegedly by a teenager living in the same foster home in western Iowa.

Vern Armstrong, an administrator with the Iowa DHS, says children are matched with foster families based on several factors, including the distance from their biological parents, and they’re often placed with other foster kids.

“That’s very common,” Armstrong says. “We actually would probably say the majority of our homes have unrelated kids placed together.” While having unrelated children placed together in foster homes is commonplace, physical aggression between them is not.

“Actually, I hear about it more when there are siblings groups placed together. There might be sibling stuff going on and they’re used to each other,” Armstrong says. “It’s rare to hear of a serious assault between one foster child and another. I can’t remember the last time we’ve had something like that.”

More than 10,000 Iowa children are placed in foster care at some point during a typical year. The state currently has around 2,100 licensed foster families.

Seventy foster children have died of natural causes in Iowa since 1997, but prior to this week, none had died from abuse. Seventeen-year-old Cody Metzker-Madsen is charged as an adult with killing 5-year-old Dominic Elkins.

The boys had lived together since early August with a foster family in a rural area of Harrison County.