Gareth Pursehouse, a 41-year-old resident of Playa del Rey and a former boyfriend of Harwick, had posted bond and was released from jail Tuesday night.
On Wednesday, a no-bail warrant was issued and he was taken into custody again.
The Los Angeles County District Attorney's Office also said Pursehouse was officially charged with the murder on Wednesday.
He was charged with one count each of murder and of first-degree residential burglary, with the special circumstance of lying wait that makes him eligible for the death penalty if convicted.
He could also face the possibility of life in prison without possibility of parole.
Pursehouse is expected to be arraigned Thursday.
Harwick, who was once engaged to "The Price is Right" host Drew Carey, had a restraining order against Pursehouse until two weeks ago, when it expired, Los Angeles police said.
Amie Harwick died of blunt force injuries to her head and torso, Los Angeles County coroner's office says
LAPD arrived to Harwick's home Saturday in the Hollywood Hills at about 1:16 a.m. and found her beneath a third-floor balcony with injuries consistent with a fall.
Pursehouse was arrested later that afternoon at his home in Playa del Rey.
Coroner's officials on Tuesday released the official cause of Harwick's death. She died of blunt force injuries to her head and torso after being transported to a hospital, according to the Los Angeles County office, which described the incident as a homicide.
Friend of murdered sex therapist Amie Harwick describes suspect as a 'stalker'
One of Harwick's friends said Pursehouse was "a stalker" who "didn't take it well at all" when the couple ended their previous relationship.