LYNBROOK, N.Y. (CBSNewYork/AP) – A Long Island couple is facing murder charges, stemming from a 2016 attack.

Ralph Keppler, a 27-year-old former correction officer, and Francesca Kiel, 21, were arrested Sunday in Lynbrook.

Authorities said they brutally attacked Kiel’s mother, 56-year-old Theresa Kiel, with a barbell on December 4, 2016 in Long Beach. She lost an eye and was in a coma until she died Saturday.

Police said Keppler and the elder Kiel were in a legal battle over a dating app they created together.

ralph keppler and francesca kiel nassau pd Long Island Couple Facing Murder Charges After Victim Of Vicious Attack Dies

(Credit: Nassau County Police Department)

Theresa Kiel’s attorney told reporters Keppler had threatened her for years.

He was previously charged with attempted murder and assault in the case but was out on bail.

Francesca Kiel’s lawyer said Monday she loves her mother and has no idea who attacked her.

The couple will be arraigned on upgraded charges Monday in Hempstead.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)