His dad murdered his mom on an African safari. Now he says the US government is 'hell-bent' on taking what's left

The son of convicted murderer Larry Rudolph says the U.S. government won't return is father's confiscated assets.

Speaking out for the first time, the son of a wealthy Pennsylvania dentist who murdered his own wife on an African vacation -- and then tried to cover it up -- says he didn't believe his father, Larry Rudolph, could do such a thing until he saw "horrifying" photos from the scene and heard soul-crushing testimony at trial last year.

In an exclusive interview with ABC News, Julian Rudolph said his father now calls him from federal prison, where he's serving a life sentence, but Julian "very rarely" picks up, unable to forgive the man convicted of fatally shooting Bianca Rudolph in 2016 so he could collect nearly $5 million in life insurance and live freely with his longtime mistress.

"It's incomprehensible to me," said Julian, now 33.

But what Julian described as equally incomprehensible is the battle he's been waging with the U.S. government for much of the past year.

"They're treating my sister and I more like perpetrators than surviving victims of a violent crime," he said.