A Philippine court has entered a not guilty plea in the case of a murdered transgender Filipino at the hands of a U.S. Marine. The Marine had refused to enter a plea, but with the plea now entered, the trial can proceed. If found guilty, the Marine could be imprisoned for life.

Justice Secretary Leila de Lima said Marine Pfc. Joseph Scott Pemberton refused to enter a plea as the trial began, reports The Associated Press. Pemberton is being charged for the murder of Jennifer Laude, 26.

The trial, scheduled for next month, can now move forward with Monday's arraignment. Protesters from the Philippines left-wing and LGBT movements have denounced the killing, demanding an end to American military presence in the island nation and calling for the case to be treated as a hate crime.

"Finally justice can be attained for our sibling," said Marilou Laude, the victim's sister. Reporters were not allowed in the courtroom.

In October 2014, Laude was found strangled in a hotel bathroom in Olongapo City, near the Subic Bay port. Pemberton was in the Philippines as part of a joint military operation and met Laude at a bar. He allegedly murdered her after finding out she was transgender.

The AFP reports the prosecution will present 18 witnesses, including a friend of Pemberton's, as well as evidence. An autopsy determined Laude died of "asphyxia by drowning."

"We have enough evidence and witnesses to convict Pemberton of murder," said Virginia Suarez, the attorney representing the family.

"He (Pemberton) was the only person with Jennifer the entire time she was in the hotel and the (motel) cashier can attest to that."

Among the witnesses is Pemberton's friend, fellow Marine, Lance Cpl. Jairn Michael Rose, who was with the accused that night. Rose said Pemberton told him he murdered Laude after discovering she was transgender.

"I think I killed a he/she," Rose said Pemberton told him.

In January the Philippines rejected an appeal Pemberton's lawyers filed to dismiss the charges, reported The Associated Press. His lawyers argued the evidence was circumstantial, but the court said the prosecution can use it in trial.

"There will be no compromise. He must pay for what he did to our sister," Marilou Laude said after the hearing. "Finally the trial is moving, finally we can get justice."