Elle Edwards, a beautician, was shot in the head at the Lighthouse in Wallasey Village and passed away at the hospital.
According to the police, a 30-year-old male was detained in Tranmere on Monday night on suspicion of murder and attempted murder.
They stated that a 19-year-old Rock Ferry woman was also detained on suspicion of planning a murder.
Detectives will question both individuals who have been taken into custody.
Four further patrons of the bar were hurt; one of them, a 28-year-old male from Beechwood in Wirral, is still needing medical care, according to the police.
Tuesday, Lucy, Elle’s sister, went to the scene to leave flowers after she had left the pub immediately before the tragic shooting.
Her ID stated: “I will always adore you, Elle May, and you will always be by my side. I adore Lucy Lou.”
A message signed “mom and dad” and bearing the words “To my lovely Elle, you are the light of my life, you will never be gone” has also been left at the site along with other flowers and tributes.
“Distinctive Daughter, the happiness you brought in your own special way, will be remembered with love each and every day,” read a heart-shaped plaque with a pink and green floral pattern.
Ms. Edwards, better known as Ellie, is not the intended victim, according to Merseyside Police.
Serena Kennedy, the chief constable, swore that her officers will pursue her killers “relentlessly.”
It “ruined so many lives and culminated in the loss of a beautiful young woman,” she said, calling her murder “sickening and heart-breaking.”
Coworkers of Ms. Edwards at the Nova Hair and Beauty Studio in Moreton, Wirral, had expressed their “complete lack of words.”
They posted on Instagram, saying, “Heaven gained the most beautiful angel, we are all heartbroken, thinking of your family right now Elle.”
At around 23:50 GMT on Christmas Eve, shots were fired at the Lighthouse’s entrance. The majority of the patrons in the pub were young.
When Ms. Edwards arrived at Arrowe Park Hospital, she was already dead.
When the shooting began, people initially believed they had heard fireworks, according to Ms. Edwards’ friend Jess.
She said to Sky News on Monday, “But suddenly, everything stopped, and we sensed something wasn’t right.
When she saw her friend on the floor being assisted by others, she claimed to feel “numb.”
Particularly from those who were present in the bar when the shooting occurred, police are requesting additional information.
Det Supt. Coombs added, “We are also pleading with local residents and drivers who may have captured anything on dashcam or CCTV to contact us because every scrap of evidence is essential to the investigation.”