The Washington Supreme Court this week struck down a law that made it a felony to unknowingly possess illegal drugs in the state.

A majority of justices ruled Thursday that the "strict liability" drug possession law, which made any illegal drug possession a felony, was unconstitutional.

“The court correctly recognized the injustice of convicting people for innocent conduct,” Richard Lechich, who argued the case before the court, told The Seattle Times. “While the decision cannot rectify the harm this law caused to so many communities, particularly communities of color, it at least puts an end to it.”

The state initially adopted the "strict liability" law in the 1950s and upheld it as "simple possession" in two instances since then. On Thursday, the justices decided that a felony conviction in a case where a person may have obtained drugs through “innocent, passive conduct" was a harsh penalty.

Mark Middaugh, who represented the Washington Association of Criminal Defense Lawyers in a friend-of-the-court brief, told the Times that the old law had been used previously against communities of color and he hopes that the new ruling can be applied retroactively for people who were previously convicted of "simple possession."

“This is a huge ruling that is going to involve thousands and thousands of cases,” Middaugh said.

The Seattle Police Department said it would follow the ruling immediately, saying officers would not arrest people, or confiscate drugs, under the simple possession law.

"RCW 69.50.4013, also known to as simple drug possession, is no longer an arrestable offense. It also cannot be used as a legal basis to seize an individual," the department said in a press release.