Defense attorneys are continuing to call witnesses in the federal conspiracy and cyberstalking trial of the widow and children of a man who killed his ex-daughter-in-law at a Delaware courthouse.

David Matusiewicz, his mother, Lenore, and his sister, Amy Gonzalez, are being tried on charges related to the death of David's ex-wife, Christine Belford. If convicted, they could face life in prison, a punishment Justice Department officials believe would be unprecedented for cyberstalking resulting in death.

Belford, along with a friend, were shot and killed by Thomas Matusiewicz, who then exchanged gunfire with police and killed himself.

Prosecutors allege that David Matusiewicz conspired for years with his parents and sister to torment and stalk Belford.

But Thomas Matusiewicz's family members have denied knowing he intended to kill Belford.