Some time Sunday evening, Marco Flores strangled, bound and beat an East Boston man in the man’s basement apartment, authorities said.

But the 17-year-old apparently wasn’t done yet.

He doused the man in a flammable liquid and returned to the Saratoga Street apartment Monday morning and lit him on fire, a prosecutor said.

Flores was ordered held without bail during his murder arraignment yesterday in East Boston District Court.

Attorneys gave little explanation of events leading up to the alleged murder.

“They went to the deceased’s room. … There was a discussion and then a confrontation,” said Ian Polumbaum, an assistant district attorney.

Authorities have not identified the victim, but family members said his name was Jaime Galdamez, 28, an immigrant from El Salvador, according to the Globe.

Attorneys said the pair knew each other for years, but did not elaborate on their relationship.

Family members at yesterday’s hearing did not want to comment and offered no more explanation of what preceded the alleged murder.

Flores showed up at the East Boston police station about 1:30 a.m. yesterday with his brother, Oscar Flores, and turned himself in. Police said that during an interview Flores “admitted to causing the death of the … unidentified male,” according to documents.

An autopsy was still being conducted yesterday to determine the cause of death, but authorities said the alleged confession was enough to charge Flores.

Flores’ attorney, Jim Budreau said that when the case goes to trial and all of the facts “come out,” a jury would likely acquit Flores.

A young suspect

Marco Flores is also from El Salvador, but court documents list his home as in East Boston.

His attorney said he is here legally and has no criminal history.

“He’s a very kind, caring gentleman who is under a lot of stress,” said attorney Jim Budreau.