Cst. Campoli arrested the appellant for impaired driving at 7:36 p.m., and read him the right to counsel and caution at 7:51 p.m. She did not read him a breath sample demand until 8:36 p.m. The appellant then spoke with his lawyer until 9:04 p.m.
 Cst. Campoli informed the breath technician, Cst. Casey, of her grounds for arresting the appellant, specifically: the appellant had been involved in a traffic accident; she observed the odour of alcohol on his breath; she observed he was unsteady on his feet, his speech was slurred, and he was unable to keep his head up. Cst. Casey testified that those were sufficient grounds for him to proceed with the testing procedure. He also indicated that it was his standard practice to review with the arresting officer his or her grounds for arrest.
 Cst. Campoli then turned the appellant over to Cst. Casey for testing. Cst. Casey read the appellant his rights to counsel, caution to a charged person, secondary caution to a charged person, and the breathalyzer test demand. After reading each element, Cst. Casey asked the appellant whether he understood it; the appellant said he did.
 As in all cases involving warrantless searches and seizures, the onus is on the Crown to prove, on a balance of probabilities, that the demand for the breath sample was reasonable: R. v. Haas, (2005), 76 O.R. (3d) 737 (C.A.), at paras. 24 and 31. A search is reasonable if, in part, it is authorized by law.
 To determine whether Cst. Casey�s taking of breath samples from the appellant was authorized by law requires answering the following question: Where the trial judge has found that a breath sample demand by the investigating or arresting officer was not made �as soon as practicable�, can a separate demand by a breathalyzer technician satisfy the requirement of s. 254(3) that a demand be �made as soon as practicable� by �a peace officer [who] has reasonable grounds to believe that a person is committing, or at any time within the preceding three hours has committed, an offence under section 253 as a result of the consumption of alcohol�?
Nevertheless, the interpretation of s. 254(3) adopted in Deruelle at p. 671
is clear: �s. 254(3) should be interpreted as requiring only that a peace officer
form a belief that an impaired driving offence has been committed by the suspect within the past [three] hours. A demand made pursuant to that belief must follow
...as soon as practicable, but this may fall outside the [three]-hour limit.�
 As applied to the present case, the interpretation of s. 254(3) in Deruelle
would permit the trial judge to find that a demand by the breathalyzer technician,
Cst. Casey, would satisfy the requirements of s. 254(3) provided he had formed
reasonable grounds within the three-hour time limit and made a demand �as
soon as practicable� thereafter.
Accordingly, the issue on this appeal then becomes whether the trial judge erred in finding that Cst. Casey�s demand that
the appellant provide breath samples constituted a lawful s. 254(3) demand.
 There is no dispute that Cst. Casey made his demand immediately following his formation of reasonable grounds to do so. Accordingly, his demand was made �as soon as practicable� in accordance with s. 254(3).