Dateline: The Night of the New Moon opens up one of California's most twisted murder plots, taking viewers through the calculated attempt on Greg Mulvihill's life.

The Night of the New Moon follows one of the more shocking cases of a bitter custody battle turning into a murder-for-hire plot.

Weldon McDavid served as a U.S. Marine for 12 years, according to his attorney, and worked as a gun instructor and security consultant prior to meeting Diana Lovejoy.

Lea McDavid, the wife of Weldon, was also called to the stand by the defense to testify about gun parts she found in her home after the police raided it following Weldon's arrest.

Diana Lovejoy, 45, and Weldon McDavid Jr., 50, are charged with conspiracy to commit murder and attempted murder in the attack on Greg Mulvihill.

Season 24 Episode 6 Exclusive: Lea McDavid, wife of Weldon McDavid, believes her husband's sentence does not match his crime.