A pregnant woman stabbed to death a week before Christmas was killed by someone she knew and whom she was comfortable to have in her home, police believe.
Detectives searching for Natalie McNally's killer also said they think they have recovered the murder weapon, which is thought to come from her home and was not brought to the property by her attacker.
It is one of 50 items that officers have seized which are being forensically examined.
Ms McNally was 15 weeks pregnant when she was killed in her home in the Silverwood Green area of Lurgan, County Armagh, on 18 December.
Detective Chief Inspector Neil McGuinness said he believed the 32-year-old woman had a pre-existing relationship with her attacker.
The Police Service of Northern Ireland (PSNI) officer said: "I'm still keeping an open mind, but my main line of inquiry is that the murder was committed by someone that Natalie knew and indeed was comfortable allowing into her home.
"I believe this was a targeted attack towards Natalie McNally."
At a news conference in Carrickfergus on Thursday, Mr McGuinness repeated his call for help identifying a man seen arriving at and leaving the street where Ms McNally lived on the night of the murder.
The detective said: "Do you really want to protect a man who could kill a woman and her unborn baby?"
Police have no information to suggest a risk to other women, he said.
He said he did not believe that Ms McNally's door was locked when her killer arrived.
"I am keeping an open mind whether this was a pre-planned attack or something that developed when the killer arrived at the address," Mr McGuinness added.
A 32-year-old man, arrested on 19 December, was released unconditionally and is no longer a suspect.
A second man, also aged 32, detained on 21 December, has been released on police bail to allow for further inquiries.
Ms McNally's three brothers were among those at a silent vigil at Parliament Buildings, Stormont for Ms McNally on Thursday afternoon.
Her brother Declan told the gathering: "Everybody in society has to redouble our efforts to end violence against women and girls in memory of our sister Natalie."