Slaying victims Alex and Macaila Marshall with their father, Phillip Marshall.

Phillip (alternately, "Philip") Marshall, 54, a career airline pilot who claimed to have once served as a contract pilot for the CIA and DEA during the Iran-Contra affair, shot and killed his two teenage children, and the family dog, then killed himself.

The apparent murder-suicide was discovered at the family home in an upscale gated golfing community in Murphys, California.

According to local news reports, teen friends of Alex Marshall, 17 (Facebook, Twitter, Instagram), and Macaila Marshall (Facebook, Twitter, Instagram), 14, noticed the siblings had not been active via text or social media updates since Thursday and went by the house on Saturday to check on them.

The last posts made by either child to Instagram and Facebook were dated Thursday night. Read the rest