The one-year-old boy believed to have been shot in the head with an air-gun has been named as Harry Studley.
Harry, from Bristol, is fighting for life in hospital after suffering a serious head injury – which officers believe may have been caused by an air-gun.
His parents, Amy Allen and Edward Studley, said: "We very much appreciate the help and support of our family, friends and local community at this very difficult time.
"We are concentrating our focus on our son Harry's recovery and would appreciate if we could have our privacy respected in order to allow us to do so."
A 24-year-old man and 23-year-old woman, who are not related to him, have been arrested in connection with the incident.
Officers are continuing to investigate the events leading up to the incident, and forensic officers remain at the scene.
Detective Inspector Jonathan Deane said: "We believe the child received the severe injury from one pellet discharged from an air weapon. Our focus is very much on unravelling the full circumstances leading up to this tragedy.
"We're not looking for anyone else in connection with what happened and at the time we are treating this as a potentially negligent act."
Emergency crews were called to a flat in Bishport Avenue, Bristol, at 4.10pm on Friday. Neighbours reportedly said they heard the child "screaming and screaming".
The Bristol Post quoted an unnamed father, who witnessed the aftermath, as saying: "I couldn't sleep last night because I just couldn't get this picture out of my head. The mother was running behind covered in blood."
Officers have also thanked the local community for their patience and understanding while extensive inquiries have been carried out.
Mr Deane added that 'reassurance patrols' would be carried out on Sunday, adding: "If any residents have specific concerns then please speak to their neighbourhood team."