Rex Heuermann’s now-estranged wife quickly came to terms with the fact he was being accused of being a perverted serial killer, according to the top cop in the case — who said she told officers, “OK, it is what it is.”

Asa Ellerup, 59, was home in Massapequa Park last Thursday when officers burst in at the exact moment her husband was busted outside his midtown Manhattan architectural firm, Suffolk County Police Commissioner Rodney Harrison told Fox 5 on Wednesday.

“When we told the wife, she was shocked, she was embarrassed,” Harrison said.

“But there was a point where we showed her certain pictures and she said, ‘OK, it is what it is.’”

The commissioner did not reveal exactly what images helped Heuermann’s wife of at least 25 years accept that he may be behind the notorious killings.

However, her husband was seen in numerous images in court documents buying apparent burner phones and posing for creepy selfies while allegedly hooking up with sex workers.

DNA from Ellerup’s own hair has been pivotal in the Gilgo Beach case, but officials say she was traveling each time the four women her husband has been accused of killing had disappeared.

Harrison previously told CNN that the reaction of Ellerup and her two kids suggested that they had no idea “about this double life” as an alleged killer.

“But, time will tell,” he told the network. “And once again, there are still a lot more questions that need to be done to the family and friends.”

Heuermann has yet to have a single visitor at the Suffolk County correctional facility where he’s being held since his arraignment Friday, Sheriff Errol Toulon Jr. told CNN.

And on Wednesday, Ellerup filed for divorce, just six days after the shock of her husband’s arrest.

She and her adult kids have had their worlds “turned upside down,” her newly retained attorney, Bob Macedonio, told The US Sun.

“Obviously this has been a shocking time for them and a pretty difficult time to comprehend,” he said.

She and her adult kids have had their worlds “turned upside down,” her newly retained attorney, Bob Macedonio, told The US Sun.

“As with any family, it’s extremely upsetting and they’re totally shocked and caught off guard.

“The family doesn’t want to make any further comment than that.”

Ellerup was pictured for the first time since the arrest with 26-year-old daughter Victoria — who worked for her dad’s architecture firm. It was not immediately clear if the man with them was her son, who neighbors say has special needs.

In his Fox 5 interview, Harrison said the breakthrough match to Heuermann’s distinctive Chevy Avalanche was thanks to a state police database — suggesting that info was not available in the 12 years before he set up the special Gilgo Beach task force.

He also let on that the fear of Heuermann’s arsenal of up to 300 guns was not the only reason he was nabbed in midtown and not at home.

“The strategy was to see if we could catch him by his workplace, take that long ride from 35th and Fifth out to 30 Yaphank — which could be a one-and-a-half hour ride — and see if he could talk and give up anything,” Harrison continued.

Instead, “He asked for a lawyer –and that was the end of the conversation,” Harrison said.