NCIS star Pauley Perrette – who plays Abby Sciuto in the hit US play to lab technician – was assaulted outside her Hollywood home on Thursday night.
The actress, who had been hit in the face several times, told Twitter followers she thought she would expire.
In a lengthy post, she described the guy as “psychotic”, adding, “I am shaken and traumatised… I nearly died tonight”.
Police said a man was later arrested for aggravated battery.
Los Angeles police officer Jane Kim confirmed the actress’s report of the assault was exact.
In her report of the assault, 46-year old Perrette described Merck as a “a QUITE psychotic homeless guy”.
“He grabbed me so forcefully, pinned my arm, punched me in the nose, brow, repeatedly telling me he was really going to kill me.”
Perrette remembered how, as she lay collapsed on the floor, a guy walked past “on his telephone, annoyed. Did nothing.”
Her tweet ended: “Tonight was horrible, life-changing and that I’m only grateful to be alive.
The performer has been with NCIS’s cast since it commenced in 2003.
The CBS show is the most-watched drama on US television. Last week’s episode was watched by means of an audience of 18 million.