Police believe they have recovered the weapon used to murder Natalie McNally in her Lurgan home, a senior detective has said.
PSNI Detective Chief Inspector Neil McGuinness said his main line of inquiry was that the 32-year-old was killed by someone she knew and was comfortable allowing into her home.
Ms McNally, who was 15 weeks pregnant, was stabbed in her home in the Silverwood Green area of Lurgan, Co Armagh, on December 18.
Police have so far made two arrests but no-one has been charged.
A 32-year-old man arrested on December 19, was released unconditionally and is no longer a suspect.
A second man detained on December 21, also aged 32, has been released on police bail to allow for further inquiries.
At a police press conference in Carrickfergus on Thursday, Mr McGuinness said he did not think there was currently a risk to other women in the area.
“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,” he said.
In regard to the murder weapon, the detective added: “I believe I have recovered what was the weapon used to murder Natalie McNally.”
Mr McGuinness said he believed the weapon was from Ms McNally’s home and was not brought to the property by her killer.
The PSNI press conference took place ahead of a silent vigil for the expectant mother at Parliament Buildings, Stormont.
Ms McNally’s three brothers were among those who attended the Stormont event on Thursday afternoon.
Her brother Declan told the vigil: “Whatever differences of opinions there are in this country we know there is no difference of opinion and everybody wants to see an end to violence against women and girls.
“And everybody in society has to redouble our efforts to end violence against women and girls in memory of our sister Natalie.”
Earlier, at the PSNI media conference, Mr McGuinness reiterated his appeal for help identifying a man seen arriving at and leaving the street where Ms McNally lived on the night of the murder.
“Our efforts to identify the man captured in the footage remains ongoing and I would appeal to anyone who believes that they recognise this person to get in touch,” he said.
“Someone must know who he is and I would appeal to you to do the decent thing to get in touch with me. Do you really want to protect a man who could kill a woman and her unborn baby? I believe Natalie knew her killer and police have no information to suggest a risk to other women.”
Mr McGuinness said officers were keen to build up a picture of Ms McNally’s lifestyle, including her friends and relationships.
He said officers have so far conducted 200 house-to-house inquiries, seized 3,000 hours of CCTV footage and sent 50 items for forensic examination.
“The deaths of Natalie and her unborn baby have left unimaginable pain and heartache to a loving and devoted family whose hearts are simply broken,” he said.
“We remain determined to bring her killer to justice and I’m asking anyone with any information to do the right thing and to speak up.”
Mr McGuinness told the press conference: “I believe that Natalie knew her killer.
I am keeping an open mind whether this was a pre-planned attack or something that developed when the killer arrived at the address— Detective Chief Inspector Neil McGuinness
“I believe that there was a pre-existing some form of relationship with her killer and someone that she was content to allow into her home, so I believe this was a targeted attack towards Natalie McNally.”
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.
The detective was asked about online rumours linking Ms McNally to a serving police officer.
“They’re not helpful,” he replied.
“We have conducted investigations into that matter and we’ve eliminated that person from inquiries.”