Mr. Kasowitz responded with four obscenity-laced emails in 33 minutes, according to ProPublica. He gave a phone number, demanded that the man call him and told him to “watch his back.”

“I already know where you live, I’m on you,” the last email said. “You will see me. I promise.”

ProPublica said the man was so unnerved by the threat that he contacted the F.B.I.

Mr. Sitrick said on Thursday that Mr. Kasowitz intended to apologize to the email writer. “While no excuse, the email came at the end of a very long day that at 10 p.m. was not yet over,” Mr. Sitrick said.

He quoted Mr. Kasowitz as saying, “The person sending that email is entitled to his opinion, and I should not have responded in that inappropriate manner.” Mr. Kasowitz added, “This is one of those times where one wishes he could reverse the clock, but of course I can’t.”

This was my wife's comma error, since fixed:

"A highlight of my day was going to the biergarten in Asbury Park with my parents, Rebecca, and Ken."

Her parents are *not* Rebecca and Ken.