A Philippine court entered a not-guilty plea Monday for a U.S. Marine charged with the murder of a transgender Filipino, who authorities say he killed after finding out her gender when they checked into a motel.

Accompanied by security escorts and his lawyers, Marine Pfc. Joseph Scott Pemberton refused to enter a plea to the murder charge in the brief proceeding in a court in Olongapo city northwest of Manila, according to Justice Secretary Leila de Lima. Journalists were barred from the courtroom.

The arraignment paves the way for Pemberton's trial, which lawyers of the victim's family said was scheduled to start next month.

"Finally justice can be attained for our sibling," Marilou Laude, the victim's sister, told reporters, adding she was shaking in anger when she saw the handcuffed suspect guarded by several escorts in the courtroom.

Dozens of left-wing protesters waved red flags outside the courthouse Monday, demanding justice for Laude and an end to U.S. military presence in this former American colony. Gay and lesbian groups have also staged protests denouncing Laude's killing as a hate crime.

Pemberton has been charged by prosecutors in the October killing of Jennifer Laude, whose former name was Jeffrey and who had apparently been strangled and drowned in a motel toilet bowl after the U.S. Marine discovered that she was a transgender woman. They had checked into the motel after meeting in a disco bar.

The anti-tank missile man from Bristol, Massachusetts, was bar-hopping with fellow Marines at the time after participating in joint U.S.-Philippine military exercises.

Among the evidence submitted by government prosecutors were statements by three Marine colleagues who were with Pemberton on Oct. 11 in Olongapo, a former liberty town when the U.S. Navy was at the vast Subic Naval base, now a bustling commercial port.

Pemberton and some of his colleagues picked up women at a disco bar and separately checked in at nearby motels, then returned to their ship after midnight. Witnesses saw Pemberton check in with Laude. He was then seen leaving shortly before the discovery of her body, prosecutors said in a statement to the court.

Marine Lance Corporal Jairn Michael Rose, who was with Pemberton that night, acknowledged that Pemberton later confided back at their ship that he attacked the woman he was with by choking her after discovering that she was a transgender when she undressed, according to the prosecutors.

"I think I killed a he/she," Pemberton was quoted as having told Rose.

The case comes after the Philippines and the United States strengthened ties with the recent signing of a defense accord that allows greater U.S. access to Philippine military camps. The accord will help Washington's bid to reassert its presence in Asia, and enable Manila to deter what it calls China's aggressive moves to reinforce its claim to virtually the entire South China Sea. (**)