Washington ? After knocking, police don’t have to wait longer than 20 seconds before breaking into the home of a drug suspect, a unanimous Supreme Court ruled Tuesday in a case involving a man who said he needed more time to get from the shower to the door.

LaShawn Banks emerged soapy and naked to find masked, heavily armed officers searching for drugs in his Las Vegas apartment in 1998. His case gave the court its first opportunity to say how long police must wait before breaking into a home to serve a warrant.

The court didn’t set a specific standard but said the brief delay in Banks’ case was long enough. Any more time would give drug suspects an opportunity to flush evidence down the toilet.

Justice David H. Souter, writing for the nine justices, said while “this call is a close one, we think that after 15 or 20 seconds without a response, police could fairly suspect that cocaine would be gone if they were reticent any longer.”

He noted the unfortunate timing of the afternoon raid, which brought Banks “out dripping to confront the police.” But police didn’t know Banks was in the shower, he said.

Banks’ lawyer, Randall Roske, criticized the ruling, saying it would lead to aggressive searches. “Police are going to read this as, ‘Knock and announce and kick the door in,”‘ he said.

The Supreme Court has said that in most cases, police armed with court warrants to search for drugs must knock and announce themselves, otherwise they run afoul of the Constitution’s Fourth Amendment ban on unreasonable searches. There are exceptions, such as when police have believe a suspect would be dangerous.

Tuesday’s ruling “gives officers the leeway they were taking throughout the country,” said George Washington University law professor Stephen Saltzburg. “This is a case that suggests great deference to the police.”