(AP) — A Springfield man has pleaded guilty to killing a southwest Missouri couple in 2011, and authorities have said for the first time they believe the case was a murder for hire.

Tony Friend pleaded guilty Tuesday to two counts of first-degree murder in the deaths of Rebecca and Russell Porter. Taney County prosecutors agreed to drop plans to seek the death penalty, meaning Friend will be sentenced to life without parole.

Five people were charged in the deaths of the Porters, who were abducted from their home in the Greene County town of Willard. They were shot and buried in rural Taney County.

Prosecutor Jeff Merrell said Tuesday he believes another defendant hired Tony Friend to kill the Porters, but he declined to discuss a possible motive.