COLUMBIA, S.C. (AP) - The mother of five South Carolina children allegedly killed by their father in 2014 says the state's social services agency knew the father was a threat and did nothing to stop him.

The allegations are part of a lawsuit filed last week by Amber Jones.

Previous Coverage: Cops Say Dad Led Them to Bodies of 5 Children | Warrant Says 5 Children Were Killed at Home

Prosecutors are seeking the death penalty against her ex-husband. Authorities say Timothy Ray Jones Jr. killed his five children at their Lexington County home in 2014 and drove around with their bodies in trash bags for several days before dumping them in an Alabama field.

Previous Coverage: DSS Had Open Investigation on Children's Father

A Social Services spokeswoman declined to comment on the lawsuit. The agency has previously released files showing that the father was visited by social workers multiple times but that authorities never found anything serious enough to remove the children.