(AP) — An arrest affidavit filed in Webster County Court says a Guide Rock woman found dead in her Guide Rock home in southern Nebraska was stabbed 22 times.

Authorities have arrested a mother and son in the Oct. 4 death of 68-year-old Virginia Barone.

Investigators say 41-year-old Shelley Casterline confessed to the killing after she and her son, 23-year-old Andrew Casterline, were arrested a day after Barone’s killing in central Iowa. The pair are accused of mugging a woman in a Newton, Iowa, parking lot on Oct. 5.

Nebraska court records say Shelley Casterline told police she and her son argued with Barone before she stabbed the woman.

Police say bank cards belonging to Barone were found on the Casterlines when they were arrested.