The trial judge decided the evidence consequently obtained from the search warrants should not be received in evidence under Evidence Act 2008 s 138. Because the warrant application wasn't sworn as required by Drugs, Poisons and Controlled Substances Act 1981 s 81(1), there was no affidavit as required, and hence the grounds for the warrant weren't met. There are similar provisions for other search warrants, contained in Magistrates' Court Act 1989 s 75(2).
The DPP appealed that decision to the Court of Appeal, arguing that the trial judge should have received the evidence.
The result was delivered last Friday in DPP v Marijancevic; DPP v Preece; DPP v Preece  VSCA 355.
The Director's appeal was refused, but there are a few nuances in the judgment that warrant close reading.
The Court of Appeal set out some of the transcript from the trial, particularly where the deponent admitted to not swearing the affidavit. He went on to say it was the only practice he'd ever seen in Victoria Police; he wasn't aware of training on the topic; and he thought he would be exposed to a possible perjury charge if he lied in the affidavit. (One of the concerns noted by the trial judge and the Court of Appeal was that the failure to swear an affidavit means the purported deponent isn't potentially deterred from fabrication and deceit because they can't be charged with perjury. I'm not sure that's as big a concern as the courts seemed to think. Presumably the police could be charged with attempting to pervert the course of justice — punishable under Crimes Act 1958 s 320 — if they spoke falsely in the search warrant application, sworn or not?)
Now some folks might scoff at the notion that a police officer could genuinely be ignorant of such a fundamental requirement as swearing an affidavit for a search warrant. However, you might be surprised to know that the police manual — VPMP Searches of Properties and VPMG Searches of Properties, for those with access to them — say precisely nothing about the need to actually swear the affidavit. (Presumably that's about to change in a hurry.) And I know that the Victoria Police Reference Guide didn't contain that detail until 2009 — because I put it there. (And that publication was discontinued this year.)
What came out fairly clearly from the police officer's evidence was that he didn't know he was doing the wrong thing: at  and . Despite that, the trial judge concluded the police conduct was deliberate and 'of the highest order': at  – .
It seems that the trial judge adopted submissions for the accused Marijancevic when His Honour made that ruling, and there was some uncertainty about what he meant by 'deliberate'. If he meant no more than 'voluntary' or 'not accidental' (or perhaps 'conscious decision to follow the practice', at ), there wouldn't be much problem. But it was argued in the County Court that 'deliberate' meant 'knowingly illegal'. The DPP argued that finding wasn't open to the trial judge.
The appeal failed on that point. Because the appeal was an interlocutory one, concerning a discretionary decision, the applicant had to show that the decision was not open to the trial judge, rather than just that he should have made a different decision: at  (citing DPP v MD (2010) 205 A Crim R 349 and House v The King (1936) 55 CLR 499) and , .
However, there was one ray of hope for the prosecuting authorities in this.
 Although we have concluded that the appeal must be dismissed we would not wish it to be thought that the discretion should necessarily be exercised in the same way were the same issues to arise again for consideration in similar circumstances. We have identified error in his Honour’s reasons and expressed our serious reservations as to various findings made by his Honour. It should not be assumed that we would have made like findings or that we would have exercised the discretion in the same way had a finding of inadvertent or careless conduct been made.
It seems the Court of Appeal was careful to say that if the issue of unsworn 'affidavits' for search warrants crop up in other cases, they'll need to be determined on their merits. In particular, if the Courts accept that the police were ignorant rather than criminal in their failure, it might be permissible to receive the evidence despite that problem.
But, the Court of Appeal was also pretty critical of the 'mere' fact of ignorance, and its comments speak pretty powerfully in favour of curial rejection of that.
The practice of not requiring the affidavits in support of warrants to be sworn on oath or affirmed.
 We should say something as to the endemic practice employed within certain sections of Victoria Police of not requiring the accuracy and truthfulness of the contents of affidavits in support of warrants to be sworn to on oath or by affirmation.
 The importance of making an affidavit in order to obtain a search warrant can hardly be gainsaid. Trials in courts in Victoria and in all other states and territories proceed upon the basis that the evidence that founds the findings of fact, which determine the guilt or innocence of those accused of crimes, is given on oath or by affirmation. Similarly, the reasonable grounds of which a magistrate must be satisfied before he issues a warrant authorising a member of the police force to enter and search land, premises or a vehicle and seize any thing or document and carry it before the Court, can only be established by evidence on oath or by affidavit.
 An affidavit is the written form of sworn oral testimony. It is an ancient method of providing evidence in court. Until 1989, whenever police needed to obtain a warrant they were required to physically attend court and give sworn oral evidence before a magistrate as to the facts relied on to support the granting of a warrant. This was a clear and long standing indicator of the significance and gravity of obtaining a warrant. The 1989 Act amended the provision to enable evidence to be given orally on oath or on sworn affidavit. The new alternative methods from 1989 onwards did not justify or contemplate a derogation of standards – the evidence was still required to be sworn.
 The fundamental role which oaths and affirmations play in our system of criminal law is readily apparent. The requirements of s 81 of the Act are not a mere technical ancillary to obtaining a search warrant. Just as courts proceed upon the basis of testimony sworn or affirmed, so do magistrates issue search warrants on the basis of testimony sworn or affirmed.
 A search warrant authorises an entrance upon property and the seizure of property which would otherwise constitute an unlawful trespass. The common law has jealously guarded private property rights and has upheld the right of property owners to exclude other people and the state. Search warrants, which are obtained ex parte, displace those rights. As the Court said in George v Rockett:
The enactment of conditions which must be fulfilled before a search warrant can be lawfully issued and executed is to be seen as a reflection of the legislature’s concern to give a measure of protection to [property] interests. To insist on strict compliance with the statutory conditions governing the issue of search warrants is simply to give effect to the purpose of the legislation. ((1990) 170 CLR 104 at )
Similarly, Lockhart J in Crowly v Murphy said:
Notwithstanding that Commonwealth and State legislation governs the law of entry, search and seizure in Australia today, it is necessary to bear in mind the fundamental legal conception of the freedom of the individual in his home or premises. It is the cardinal principle in the light of which the statutory authority for the issue and execution of search warrants is read. Even today, there is no right of common law to enter a person’s home or premises for the purposes of search or seizure without the permission of the owner or occupier, except in the case of a search for stolen goods. Entry without such permission or authority of a valid warrant is to commit a trespass and to render the trespasser liable to damages. ((1981) 52 FLR 123 at 142)
 To proffer to a magistrate material which is not sworn or affirmed in order to obtain a search warrant has a tendency to subvert a fundamental principle of our law.
Those are pretty strong words and don't sound very much like acceptance of the practice. It's a pretty safe bet there'll be a lot more argument on this topic for some time.