Touching floral tributes were left outside the house where a young man was shot dead "through the window".
Michael Rainsford was killed on Tuesday night when a gunman opened fire on his home at Harrington Road in Litherland shortly after 11pm.
The 20-year-old died at the scene as emergency services rushed to save him.
A murder investigation was launched by Merseyside Police who are currently hunting the armed killer.
Tributes on social media quickly poured in for Mr Rainsford as loved ones taped flowers and heartbreaking messages to a post facing his home.
One note, which referred to the victim as "Mikey", said: "Mikey, so sad that you have gone. You are truly missed down here.
"You will never be forgotten."
Another, which described him as an "angel", also said: "No words will describe how much you will be missed.
"Rest in peace my angel."
In a short update on Wednesday night, Merseyside Police said they had launched an "extensive" operation to find Michael's killer.
And they asked for anyone with CCTV or dashcam, along with people with information about the deadly attack, to speak to them.
Neighbours told the ECHO that they heard "two bangs" before rushing out into the street when they watched as Michael's family tried to save his life.
A number of friends also shared their heartbreak on Facebook shortly after the murder.
One person said "Absolutely heartbroken, he had his whole life in front of him."
Another added: "RIP Mikey.
"Can't believe it, far too young, one of the nicest lads ever. God must only take the best.
"Shine bright up there."
Results of a post mortem examination are expected on Thursday to establish the exact cause of Mr Rainsford's death.
Detectives have described the murder as "violent and tragic."
A Merseyside Police spokeswoman said: "An extensive investigation is ongoing to locate those responsible and officers are urging anyone with information, dashcam or CCTV footage from Harrington Road or the surrounding areas to come forward.
"The victim’s family have been informed and are being supported by officers."
If you can help the investigation, contact them on Twitter, at @MerPolCC, 101 quoting ref. 20000205585 or @CrimestoppersUK, or ring anonymously on 0800 555 111.