A man and a woman have been arrested following the fatal shooting of council worker Ashley Dale in Liverpool on Sunday, Merseyside Police said.
The 28-year-old was found with gunshot wounds in her garden in the Old Swan area and was taken to hospital where she was pronounced dead.
Police investigating the killing previously released CCTV footage of a car being driven in the area, shortly before the incident was reported.
A cordon remains in place while investigations continue, and CCTV and forensic enquiries are being carried out in the local area.
Her family paid tribute to their "shining light" and said "our hearts are broken into a million pieces".
Following the arrest of two people, detective chief inspector Cath Cummings said: "Our thoughts remain with Ashley Dale's family and friends following this appalling incident which led to her tragic death.
"Our officers have now made two arrests last night. Enquiries continue to establish the motive behind this attack, and identify all those involved.
"This was a callous attack carried out on a residential street which has brought tragedy to the heart of a community in Merseyside, and we will leave no stone unturned in our efforts to bring those responsible to justice.
"Although we have made two arrests we still need members of the public to come forward with information too so we can keep our streets safe.
"From extensive ongoing CCTV enquiries, Detectives know there were people walking close to the scene at the time of the offence. If this was you, please come forward as you may without realising hold vital information to assist this investigation
"Similarly, I would ask taxi and delivery drivers if they were driving in the area between 12.20am and 12.40am and have dashcam footage please contact us."
Information can be submitted through the online portal directly to the police.
Alternatively, you can contact the independent charity Crimestoppers anonymously, on 0800 555 111 or via their online form at: https://crimestoppers-uk.org/give-information/give-information.