A court document says a 15-year-old inmate strangled a jail guard for more than 2½ minutes after he lured her into his cell.

Scotts Bluff County jail guard Amanda Baker died Sunday after she’d been declared brain dead by doctors. The attack took place Friday.

An arrest affidavit filed by a Scotts Bluff County sheriff’s investigator says security video shows the boy, Dylan Cadeilhac, talked the 24-year-old Baker into checking something on his cell floor. The affidavit says  Cadeilhac, of Torrington, Wyo.,  pounced on Baker from behind and strangled her after she fell to her stomach on the floor.

He likely will be charged Tuesday.