By Debbie Emery - Breaking Celebrity News Reporter

It has been 18 months since Josh Powell killed his two young sons and then himself, and a new report Thursday concluded that social workers could have done more to prevent the tragic murder-suicide.

A panel found that the Washington Department of Social and Health Services should “make concerted efforts” to check with detectives prior to making changes in parent-child contacts when there is an active investigation, such as Powell still being the prime suspect in his wife, Susan's disappearance in 2009, reported the Washington Post.

As Breaking Celebrity News previously reported, Powell heartlessly attacked his children, 7-year-old Charlie and 5-year-old Braden, with a hatchet before torching his home in Washington state last February. All three died of smoke inhalation.

The horrific act occurred during a supervised visit with social worker Elizabeth Griffin-Hall