The husband of philanthropist Barbara Weiden Schwartz Fischler is bringing a civil suit against his son, Jonathan Schwartz, who murdered his mother in July 2011. The suit claims wrongful death, according to Courthouse News Service.

Jonathan Schwartz stabbed his mother to death in her Upper East Side home. Police indicate that he tried to make the death appear to be a suicide by placing the knife in her hand, but later confessed to the crime in writing.

“Nothing happened today to cause me to kill my mother,” he wrote. “I’m terribly sorry this happened. This is the worst thing I have ever done.”

He was deemed unfit to stand trial due to schizophrenia, says the Courthouse News; a jury found him not criminally responsible because of mental disease. He is held at the Mid-Hudson Psychiatric Hospital.

Barbara Weiden Schwartz Fischler reportedly oversaw the family foundation. Work from her estate was sold off at the European, American, Modern & Contemporary art sale at Doyle in May 2012.

The family has been dogged by tragedy and more routine misfortune. After Schwartz murdered his mother, her second husband lost millions of her money on bad investments and was barred from administering her estate. Her other son, Kenneth Schwartz, committed suicide in 2013 after learning that his inheritance had been wiped out.

Her $5 million account with Charles Schwab had been reduced to just $700,000, according to DNAinfo.

The suit, seeking unspecified damages, is being handled by attorney Linda Genero Sklaren of the firm Warshaw Burstein, with offices on Fifth Avenue in Manhattan.