Updated

A Philippine court found three police officers guilty on Thursday of killing a student they alleged was a drug dealer, in the first known such conviction under the president's deadly crackdown on drugs.

Regional Trial Court Presiding Judge Rodolfo Azucena Jr. ruled the officers murdered Kian Loyd delos Santos during raid in a slum in the Manila metropolis last year. It rejected the policemen's claim that the 17-year-old fired back while resisting arrest.

The court sentenced the officers to up to 40 years in prison without parole, although they can appeal. Aside from the prison term, the policemen, who appeared in court in handcuffs and in yellow detainee shirts, were ordered to pay damages to Santos's impoverished family.

Duterte's crackdown, which has left thousands of suspects dead reportedly in clashes with the police, has alarmed Western governments and U.N. rights experts and horrified human rights watchdogs. The volatile president has stressed he does not condone extrajudicial killings, although he has repeatedly threatened drug suspects with death and has assured police he would back them up in ways that human rights watchdogs say have encouraged law enforcers to act with impunity.

"A shoot first, think later attitude can never be countenanced in a civilized society. Never has homicide or murder been a function of law enforcement," Azucena said in his ruling. "The public peace is never predicated on the cost of human life."

Duterte's government called the ruling "a triumph of justice," which disproved critics' assertion that the judiciary was a rubberstamp.

"As we have always stressed, the conduct of the government's anti-illegal drug campaign is based on accountability. Therefore, we do not — and we will never — tolerate unjustified police violence, brutality or killing," presidential spokesman and chief legal counsel Salvador Panelo told a news conference.

Opposition Sen. Risa Hontiveros, who has railed against the drug killings, said the court decision proved that extrajudicial killings under Duterte's crackdown were really being committed by rogue members of the national police force.

"This is a light in the darkness," Hontiveros said in a statement. "Despite the gruesome climate of killing and impunity in the country, this verdict sends the message that there is hope and justice. And we will fight for more light and truth until the darkeness cannot overcome them."

Hontiveros said the numbers of drug killings, which started to rise when Duterte took office in mid-2016 and launched his trademark war against drugs, could not have reached "catastrophic levels if these killings did not have a sinister principle and policy behind them."

Duterte and police officials have repeatedly stated there was no state policy to kill drug suspects illegally.