How Bitter Divorce and Custody Battle Led to a Calif. Mom's Murder-for-Hire Plot Gone Awry

The mysterious call came in around 10:30 p.m. on Sept. 1, 2016. A male voice on the other end of the line told Greg Mulvihill, who had spent the previous year in a custody dispute over his infant son, Kale, that he was holding incriminating evidence against him.

The evidence, the voice said, would be taped to a utility pole along a dirt path off Avenida Soledad in Carlsbad, California.

Determined to discover what was going on, Mulvihill grabbed a flashlight and his son’s mini-baseball bat, asked a neighbor to accompany him and headed to the deserted trail. Once there, the two men heard a rustle in the bushes, saw the barrel of a gun and then the flash of gunfire.

Mulvihill, 47, was struck in the side but survived.

The shooting shocked the beachside community, as did the revelations it triggered. One week after the attack, authorities arrested their prime suspect: Mulvihill’s estranged wife, Diana Lovejoy, a triathlete and software technical writer.

Investigators suspected that Lovejoy wasn’t happy with their 50-50 custody arrangement and having to pay him $120,000. Adding to the shock, investigators said she hired her firearms instructor and one-time lover, former Marine Weldon McDavid, to fire on Mulvihill.

“She was going through a contentious custody dispute and she hired Weldon McDavid to shoot her husband and eliminate the problem,” Carlsbad Police Department Sgt. Darbie Ernst tells PEOPLE. “It is as straightforward as possible.”

On Nov. 13, a jury agreed and found both Lovejoy, 45, and the 50-year-old McDavid guilty of attempted murder and conspiracy.

After hearing the verdict, as McDavid wept, Lovejoy reportedly collapsed and had to be taken to a local hospital.

Though both Lovejoy and McDavid maintain their innocence — with their attorneys arguing that there was no actual intention to kill Mulvihill — they are expected to be sentenced on Dec. 12.

She faces up to 25 years in prison. He could spend 50 years behind bars.

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Authorities say it was the battle for custody of Kale that sparked the murder plot. Lovejoy, who had accused Mulvihill of raping her while she slept and of molesting their son, secured a restraining order against her ex before the divorce. (Mulvihill has denied all of Lovejoy’s claims.)

McDavid’s later actions, his former attorney tells PEOPLE, were based in a “misguided hero complex.”

Carlsbad Police Department lead investigator Scott Stallman, who is now a San Diego County district attorney investigator, says McDavid and Lovejoy began planning to get rid of Mulvihill in the summer of 2016.

However, their scheme quickly unraveled after the shooting.

Stallman says investigators discovered surveillance footage of Lovejoy in August 2016, purchasing the burner phone McDavid used to call Mulvihill that September night last year.

She and McDavid planned to kill Mulvihill during the next new moon — Sept. 1, 2016 — when it would be “completely dark,” Stallman says.

Adding to the mounting evidence, investigators found the AR-15 that was used to shoot Mulvihill in the garage of McDavid’s home and cell-tower data placed both him and Lovejoy near the hiking trail the night of the shooting. According to police, she planned to pay him $2,000 and drove him to the area.

DNA found near the trial also placed McDavid at the scene of the crime, authorities said.

“This case is pretty bizarre,” Ernst says, “but we found the evidence quickly.”