Ex emailed Catherine Kassenoff that he ‘will never stop’ before her assisted suicide

The ex-husband of a Westchester attorney and mother who allegedly took her own life in an assisted suicide following their long and brutal custody battle emailed her that he would “never stop protecting” their three children from her just months earlier.

Allan Kassenoff, also an attorney, emailed Catherine Kassenoff on March 19 claiming that her goal was to “destroy” him in hopes that he would stop trying to protect their three girls from her, according to a copy of the email posted online by the mom and obtained by The Post.

A few months later, Catherine, 54, reportedly died by assisted suicide in Switzerland on May 27, according to a now-deleted suicide note she posted to Facebook the same day.

In the note, she claimed Allan was the villain.

She wrote that she’d recently been diagnosed with terminal cancer — but said she decided to die due to Allan’s alleged abuse and a “predatory” court system that cut her off from her girls, ages 9, 12 and 13, in 2018.

In addition to her public suicide note, Catherine posted a Dropbox folder that included the email as well as thousands of court filings, medical records, videos and more to show that her kids were taken away as a result of “unfair rulings,” “a disgraced custody evaluator,” a money-motivated attorney for the children, and the court favoring the “monied party,” she said.

The folder link is no longer available.

Allan listed how much money he spent on the custody battle — totaling more than a million dollars — over the past 11 months in the email to his ex.

He reportedly spent $3 million over the years.

“You must really be proud of yourself for financially decimating me and the children,” he wrote. “But make no mistake, no [one] is fooled Catherine; everyone knows that your goal is to destroy me and you don’t care what that means to the children.”

Allan also said he would never stop “protecting” their daughters.

“You have done all of this in hopes that I would give up and stop trying to protect the children from you. I won’t,” he wrote. “Even if this Court awards you my last dollar, I will never stop protecting them. Until the day I die.”

Catherine’s suicide letter noted his relentlessness.

“Their father has spent years and millions of dollars — over $3 million — to eliminate me from our girls’ lives … He will never relent … As long as I am alive and want to see them, they will be damaged over and over again with every attempt I make,” she wrote. “What is the point of that? The last thing I want to do is make my own children suffer.”

Allan had also emailed that all his ex knew was “hate and vengeance” against him.

“Instead of focusing on getting help, you have focused your rage on destroying me,” he claimed in the email.

Videos Catherine posted online, that were later shared on TikTok, however, show Allan as the one throwing the word “hate” around.

“I hate you,” he screamed at Catherine in one video and called her a “fat, old loser” in another posted by TikToker @therobbieharvey.

The mother was denied visits with her daughters, despite having no criminal history, mental health issues or history of substance misuse, she claimed.

“I cannot survive this torment and the grief that comes from such a prolonged separation from my children,” she wrote in her suicide note. “The court system did this to me … It is a predatory system that functions in darkness — through ‘gag orders’ like the one in my case, through a publicly-inaccessible docket, through a closed courtroom, and through ex parte ‘temporary’ orders that are in place for years.”

No friends or family of Catherine have heard from her since that day.

According to Ms. Magazine, attorney Wayne Baker, the executor of Catherine’s estate, said he is awaiting definitive confirmation of her death, which could take four to six weeks.

In the time before her death, the court found that at least some of Catherine’s allegations about the “unfair” custody proceedings were true.

The custody evaluator who recommended Allan get sole custody of their girls was removed from a number of courts after photos surfaced of the judge presiding over the custody case officiating the evaluator’s wedding.

And the same month that Allan emailed Catherine, the family’s therapist issued a report urging the court to give the mother more time with her daughters, according to a document in the defunct Dropbox files.

Following his ex-wife’s apparent suicide, Allan took a voluntary leave of absence from his employer, the law firm Greenberg Traurig, to focus on his family.

The firm is conducting an internal investigation into the situation, it said in a statement.

Allan’s attorney Gus Dimopoulous denied that the court acted unfairly in favor of his client when reached by The Post.

“At every stage of this four-year custody dispute, the court system has acted responsibly and thoroughly,” he said in a statement. “Following a neutral forensic evaluator’s assessment, the court ordered an immediate order granting their father sole legal and physical custody. The court also issued an urgent order of protection against Ms. Kassenoff eliminating unsupervised interactions with the children based on what they observed when they were with their mother.”

He added that the children have been under their father’s care for three-and-a-half years and are “safe and healthy.”

If you are struggling with suicidal thoughts or are experiencing a mental health crisis and live in New York City, you can call 1-888-NYC-WELL for free and confidential crisis counseling. If you live outside the five boroughs, you can dial the 24/7 National Suicide Prevention hotline at 988 or go to SuicidePreventionLifeline.org.