The prime suspect is the victim’s ex-boyfriend, who the victim had reported to police for stalking and threatening behaviour earlier this year after a relationship that lasted only a few months.
It ended because of the man’s abuse, according to initial reports.
Her body was found near her home in the centre of the southern city.
The woman, a cook in a restaurant, reportedly called the police because she noticed a man’s presence, but the officers could not get there in time to save her.
The police were also alerted by neighbours, who heard her screams.
The suspect, also a Moroccan national, had been issued a restraining order forbidding him from approaching the woman and ordered to wear an electronic tag, although this was not applied because of a technical problem, the sources said.
Then in July a warrant for him to be taken into custody was issued, but it was never executed because the man is homeless and the authorities were unable to track him down, the sources added.
He was detained in Rome on Thursday, his clothes still stained by blood, sources said.
On Wednesday, the suspected killer in another shocking femicide case, 27-year-old Stefano Argentino, committed suicide in prison.
He was accused of murdering Sara Campanella, a 22-year-old student, with a stab wound to the jugular in a Messina street in March.
Last month the Senate on Wednesday unanimously approved a bill making femicide a specific felony in Italian criminal law.
The bill punishes with life imprisonment anyone who causes the death of a woman “with acts of discrimination or hatred towards the victim because she is a woman, or if the criminal act is aimed at repressing the exercise of the rights, freedoms or personality of the woman”.
The bill also sets new conditions for prison incentives and privileges for femicide convicts and strengthens obligations for educational and awareness initiatives to combat gender-based violence.
The bill has moved to the Lower House for final approval.
ANSA