Decades after his father vanished, one man wonders what role a murderous boss may have played

The phone call was chilling.

Ken Holmgren didn’t talk to his father often, but during that February 1991 call, Elmer Holmgren told his son that if he didn’t hear from him again in a few days, he should call an agent with the ATF, the federal agency now known as the Bureau of Alcohol, Tobacco, Firearms and Explosives.

“Panic struck,” Ken Holmgren, 71, told “Dateline.” “I really didn’t know who he was working for.”

He said he knew that his father, a lawyer who’d struggled to find work after the death of his employer in Florida, had moved to Las Vegas and was working for a wealthy couple, Kenneth and Sante Kimes.

But Ken Holmgren didn’t know about Sante’s lengthy criminal history, mostly for theft-related charges, he said. Nor did he know that she’d recently served three years in a federal prison for charges of indentured servitude. She and her husband — who took a plea agreement in the case — had been accused of abusing young undocumented women whom they’d recruited to work as housekeepers.

Holmgren never heard from his father again. But less than a decade later, Sante Kimes captured national attention with a pair of brutal and puzzling crimes that spanned thousands of miles. Sante Kimes and her younger son, Kenny Kimes Jr., were charged and convicted in separate trials in connection with two 1998 murder plots — the killing of a New York City socialite, Irene Silverman, and the fatal shooting of a Los Angeles businessman, David Kazdin.

During his trial for Kazdin’s killing, the son confessed to a third murder — the killing of a bank executive who’d gone missing in the Bahamas in 1996 while investigating irregularities in the Kimes’ offshore bank accounts.

Now, decades later, the mystery of what happened to Elmer remains. As does his son’s frustration that, in his view, authorities never seemed to have sought answers in the disappearance. Holmgren said that it’s even more maddening given that when he vanished, his father was cooperating with the ATF as a witness against Sante Kimes and her husband in a suspected arson at their Honolulu home — an arrangement that Holmgren said he later learned of from a special agent with the ATF.

“If the ATF would have done their job, there would have been several more people that wouldn’t have lost their lives,” he said. “That’s the way I look at it.”

A spokesperson for the ATF would not comment. The person Holmgren…