This was despite the fact possible suspects were known to police and they were already the subject of an ongoing investigation. Officers arrived at the scene about 2½ hours after the incident was first reported.

A person or persons unknown had fired two rounds, believed to be from a 12 gauge shotgun, into the side of a Toyota parked outside a home where a single mother and her three children were sleeping about 5am. The woman did not notice the damage until she went out to the shops later in the day and police say they received their first phone call at 2.29pm from a woman.

While the woman, who is still badly shaken by the incident, does not want to be named, her father, Graham Wilson, is irate that police did not arrive at the scene until almost 12 hours after the attack, that the matter was not made public and no appeal for witnesses was made.

"When police were advised by the complainant that 'this most likely happened last night' the response priority was scaled back to a Criminal Damage Priority Three in accordance with our Priority Response Model,'' an ACT Policing spokeswoman said.

Priority Three is the lowest ranking on the response model and does not require police to attend a crime scene. The December incident is believed to be only the second shotgun attack in the ACT in 2012.

"There are two possible responses to situations where there is no immediate danger to safety or property,'' the AFP purchase agreement with the ACT government states.

"This will be either police attention or police response. A determination will be made as to whether the complainant agrees that the matter can be handled over the telephone (police attention) or if attendance is required. If the latter, then attendance must be not later than 48 hours from the initial contact.''

ACT Policing initially told Fairfax police had attended the scene at 5am, almost seven hours before the first report to Triple-0. On being asked to clarify the apparent discrepancy, ACT Policing said: "the first call for police assistance was made some nine hours after the incident is alleged to have occurred, at 2.32pm, a little over two hours after the complainant noticed the damage." Police arrived about 5pm.

Mr Wilson believes his daughter first contacted the police before noon but ACT policing have no record of this. ACT Policing also said that when officers from Tuggeranong arrived at 4.49pm they spoke to the complainant and requested forensics support. A doorknock of the neighbourhood was also carried out.

"It should be noted that the complainant has not responded to police phone calls (on Monday),'' the spokeswoman said. "Police officers have since gone to her house to seek her statement.''

Asked why police had not taken a statement before Tuesday, the spokeswoman said: "At the time (December 27) the complainant was not prepared to provide a statement. Statements are not always taken at the time of the incident. For example if the complainant appears intoxicated or drug affected police are duty bound to return at a later date for the interview to ensure the integrity of the statement."

Mr Wilson told Fairfax he had no recollection of his daughter either refusing to speak to police or being incapable of doing so.