FARGO (AP) - A 16-year-old who pleaded guilty to killing his sister in Fargo last summer was moved to the Cass County Jail from a juvenile detention center about 12 hours after a detention center guard was attacked in a failed escape attempt.

Because Sergei Carlson is younger than 18, officials won't disclose if he was one of two suspects in the attack.

The female guard suffered minor injuries Thursday when struck with a piece of wood from a bookcase.

Carlson pleaded guilty Sept. 15 to charges of murder and a deviate sexual act in the death of his 16-year-old sister, Whitney.

He's to be sentenced Oct. 23 and faces up to life in prison.