MANILA, Philippines — A U.S. Marine has asked a Philippine court to reverse his conviction in the killing of a transgender Filipino and sought a bail and a reduction of his six to 12-year jail term, his lawyer said Wednesday.

Lawyer Rowena Garcia-Flores said she would insist that her client, Lance Cpl. Joseph Scott Pemberton, did not kill Jennifer Laude in a motel room after they met in a disco bar in October 2014 and that his sentence should be eased because he surrendered to authorities.

In December a judge convicted Pemberton of homicide, not the more serious charge of murder as prosecutors sought — and sentenced him to a lighter jail term than what the victim's family sought.

The regional trial court judge in Olongapo city, northwest of Manila, said she downgraded the charge because conditions such as cruelty and treachery had not been proven.

The court will start to hear Pemberton's appeal on Thursday.

"We're going for an acquittal," Flores said by telephone. "He defended himself because he felt he was being conned but he did not kill Laude."

In case the court upholds the conviction, Flores said she and other defense lawyers asked the court to consider easing Pemberton's sentence because he surrendered to authorities and that he had "no intention to commit so grave a wrong."

The killing sparked anger in the Philippines and reignited calls by left-wing groups and nationalists for an end to America's military presence in the country at a time when the U.S. is reasserting its dominance in Asia and Manila has turned to Washington for support amid an escalating territorial dispute with China.

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Pemberton, an anti-tank missile operator from New Bedford, Massachusetts, was one of thousands of American and Philippine military personnel who participated in joint exercises in the country in 2014. He and a group of other Marines were on leave after the exercises and met Laude and her friends at a bar in Olongapo, a city known for its nightlife located outside Subic Bay, a former U.S. Navy base. At least two witnesses testified that Laude was a sex worker.

Pemberton, 21, has been detained at a compound guarded by Philippine and American security personnel, at the main military camp in metropolitan Manila, and not in an ordinary jail as demanded by Laude's family.

The emotional case has sparked concerns about special treatment for visiting American forces, and left-wing activists have called on the government to fight Pemberton's appeal.

Another Marine, Lance Cpl. Daniel Smith, was found guilty and sentenced to life in prison on charges of raping a Filipino woman in 2005. He was held at the U.S. Embassy in Manila until a Philippine appeals court overturned his conviction in 2009, allowing him to leave the country amid anti-U.S. protests.

"If we allow Pemberton's conviction to be reversed or reduce his sentence, this will send a wrong message to U.S. soldiers: That they can commit crimes and get away with it," left-wing activist Renato Reyes said.