Prosecutors in the Philippines have filed murder charges against a US marine accused of killing a Filipino transgender woman in a case that has fanned anti-American sentiment.

Prosecutors found probable cause against Pte First Class Joseph Scott Pemberton and decided that he used “treachery, abuse of superior authority and cruelty” against his alleged victim, lead prosecutor Emilie Fe delos Santos told a televised briefing.

“You can see the kind of cruelty she endured, the injuries she sustained,” Delos Santos said. “We believe we have a strong case.” Pemberton will not be allowed to post bail, she said. Murder is punishable by up to 40 years in jail.

Jennifer Laude, a 26-year-old transgender woman also known as Jeffrey, was found dead on 2 October in a hotel, in the port city of Olongapo. She was discovered half-naked in a bathroom with marks of strangulation on her neck, according to police. Laude died from asphyxia by drowning, according to a police autopsy.

“This is not an ordinary murder. This is heinous because she was beaten up,” the Laude family lawyer, Harry Roque, told reporters.

Pemberton, who had just finished taking part in US-Philippine military exercises near Olongapo, had checked into the hotel with Laude and was the last person seen with her. Police said Pemberton, aged 19 at the time of the death, had asked prosecutors to downgrade the murder charge to homicide, which carries a maximum 20-year prison term.

Laude’s death sparked street protests and the public outcry pressured the Philippine government to seek the transfer of Pemberton’s detention from a US warship to military headquarters in Manila.

Under a 1998 agreement governing US troops when they are in the Philippines, Filipino courts have jurisdiction over cases involving American soldiers accused of crimes. But the agreement also allows suspects to remain in US custody.

“We look forward to the full cooperation of the US government in ensuring that justice is secured for Jeffrey ‘Jennifer’ Laude,” foreign ministry spokesman Charles Jose said in a statement. The US embassy had no immediate comment.

President Benigno Aquino has said the case should not sour relations with the US, the Philippines’s most important diplomatic and military ally. “Name me any place that doesn’t have any crime. And the sin of one person should be reflective of the entire country? I don’t think so,” Aquino said in October.

Following formal charges by prosecutors, the court with jurisdiction over the case will decide whether there are enough grounds for the accused to stand trial, although there is no timetable for this process.

The case is the second major test of the 1998 visiting forces agreement. In 2006, US marine Lance Cpl Daniel Smith was sentenced to 40 years in jail after being found guilty of raping a woman a year earlier. Smith, however, walked free in 2009 after his accuser recanted her statement, prompting an appellate court to acquit him.