Two guns were used in the shooting which killed Olivia Pratt-Korbel as CCTV shows the shooter running from the scene.
Merseyside Police released the CCTV of the gunman during a press conference.
The nine-year-old was shot dead during a bungled assassination on August 22 when a gunman fired into her family home at around 10:00 pm.
Detective Chief Superintendent Mark Kameen described the gunman as wearing a black hooded jacket, black balaclava with black gloves and black trainers with distinctive white soles.
Police also released footage of a man they want to speak to who was in the area at the time of the shooting.
He said: “I am going to show you footage of the man that murdered little Olivia. I am doing this because people may recognise what he is wearing. It may also help people remember seeing him in the area on the night of Olivia’s murder and be able to help us trace where he went next.
“This footage shows the gunman running along Finch Lane away from Kingsheath Avenue. You then see him turn right into Berryford Road and go out of sight. We know he is climbing into and through people’s gardens to avoid being seen.
“As you can see, the gunman was wearing a black padded jacket and a black balaclava with a peak and black gloves and he is described as approximately 5ft 7in tall with a slim build.
“This is the man we are hunting for – We need to know where he went that night or did you see him in the area? Remember this was shortly after 10pm on Monday 22nd August.
“I know that there will be people shielding and helping this man. If you are found to be doing this then we will do everything legitimately possible to bring you to justice. It is beyond comprehension how anyone can protect a person who is responsible for killing a nine-year-old little girl.”
He continued: “”This man is toxic. He is toxic to our communities and if you are protecting him then he is toxic to you and your families.
“I want you to place the loyalty that you have to you families before any loyalty you have for this man. I want information as to where he is now.
“The investigation team have worked closely with partners within the forensic arena and the National Ballistic Intelligence Service (NABIS) and I can now confirm that there were two guns used during this attack.
“I believe at this time that the gunman brought both of these weapons with him and that they were still with him when he callously ran away from Olivia’s house. I want to know where those guns are now.
“You may have been told to hide them or dispose of them – I understand you may be frightened of contacting us, but I want you to do the right thing for Olivia and tell us where they are right now.
“If you are hiding the guns and you have no intention of telling us, then I place you in the same category as the vile man responsible for the murder. And we will hunt you too.
“I would repeat the fact that the actions of the person who carried out this cold-blooded attack do not command loyalty in any way, shape or form and Olivia’s family need to know that everyone responsible for her murder has been caught and convicted.”
He added: “I therefore want to trace this man who was in the area at the time. He is stood on Finch Lane near to the junction with Kingsheath Avenue.
“I am interested in speaking to him as he may have information that is important to the enquiry.
“I therefore appeal for this man to come forward and make himself known to the investigation team. If anyone knows who this man is, please tell us.”
He also told reporters that part of the force’s efforts in disrupting organised crime included executing 88 warrants, doing a stop-and-search of 942 people, arresting 349 and conducting open land searches.
Mr Kameen thanked the public for the “huge amount of information” they had provided to police.
He said Olivia’s mother Cheryl was still being treated for her injury and was “incredibly thankful” for the care and compassion from the community.
Olivia was at home with her mum Cheryl Korbel and older siblings when the gunman attempted to force entry and fired shots into the Dovecot address.
The killer had been targetting Joseph Nee, who forced his way into the house when Ms Korbel opened the door to see what was going on outside.
Despite Ms Korbel’s attempts to keep the gunman out, he managed to fire a shot which hit the 46-year-old in the wrist and then struck Olivia.
He then wounded Nee in the torso and legs.
The killing happened on the 15th anniversary of the shooting of 11-year-old Rhys Jones, who died in the same city after being gunned down by teenager Sean Mercer in a failed attempt to target gang rival Wayne Brady.
Anyone with information is asked to DM @MerPolCC or call @CrimestoppersUK anonymously on 0800 555 111 quoting log 22000621096. You can also pass information on our Major Incident Public Portal website mipp.police.uk