IN old movies, police officers hammering on front doors customarily shout: "Open up in the name of the law" as they home in on their criminal quarry or seek out vital evidence to nail a villain.

In Scotland in real life, such scenes include another feature: a search warrant authorised by a Procurator Fiscal and issued by a sheriff, magistrate or justice of the peace.

Now the Association of Scottish Police Superintendents (ASPS) is seeking a change in the law to give senior police officers the power to issue search warrants themselves. There are already limited circumstances in which police officers can enter private premises without a judicially-approved warrant. Officers in hot pursuit of a suspect, for example. But once a suspect is already under arrest at a police station, police are required to seek a warrant before they can enter the suspect's property to seize evidence such as illegal drugs, firearms or stolen goods. In some cases investigations can be held up while an officer waits for a busy sheriff to sign off a warrant.

Their demand must be seen in the context of the Cadder judgment, which gave suspects in custody access to legal advice. In some instances it may take so long to obtain a warrant that the suspect has to be released before the search for evidence is authorised.

In England and Wales entry and search powers became available to police under the 1984 Police and Criminal Evidence Act.

That is not a reason per se for police authorising their own search warrants in Scotland. Such operations must always represent a balance between the powers of the police, the protection of the public and the rights of individuals. The role of the judiciary is to test the reasons for an action, which in normal circumstances would be regarded as a breach of human rights. In the overwhelming majority of cases, warrants are granted. Where they are refused, it is likely to be because officers have failed to justify their request.

The ASPS says that giving the power to grant warrants to a senior officer would not result in speculative "fishing expeditions". Without independent oversight, how could that be guaranteed? What would prevent such authorisations becoming a rubber-stamping exercise?

No such change is recommended in Lord Carloway's recent review of Scots criminal law and practice. If the ASPS wants to win this argument, it will need to produce concrete examples where the ends of justice have been defeated by the delay in obtaining a search warrant.

Even then, this would not in itself justify allowing the police to police themselves in this respect. Another solution is one suggested last year by Labour MSP Graeme Pearson, former head of the Scottish Crime and Drug Enforcement Agency. Rather than insisting on a face-to-face meeting between a police officer and the sheriff (or magistrate, or justice of the peace), he suggests the whole operation could be handled via Skype or a video link.

Long delays in granting warrants are not in the public interest because they offer opportunities to destroy evidence and waste police time. But the answer may be to bring the administration of Scottish criminal justice into the 21st century rather than give the police more powers and less oversight.