BOSTON — An ex-convict was ordered held without bail Tuesday as a prosecutor described how he allegedly fatally shot four people – including a 2-year-old boy and his mother – during a drug robbery in Boston.

In a courtroom packed with friends and relatives of the victims, not guilty pleas were entered for Dwayne Moore, 33, on charges of murder, armed robbery and home invasion.

Moore, who prosecutors said was released from prison earlier this year after serving a 10-15 year sentence for manslaughter, did not appear in the courtroom.

He stood behind a door that was slightly open so he could hear the charges, but he was not visible to most people in the courtroom.

Moore’s court-appointed lawyer, John Amabile, said his client “vehemently denies” any involvement in the slayings.

Killed in the Sept. 28 shootings were 2-year-old Amani Smith; his mother, 21-year-old Eyanna Flonory; her boyfriend, 21-year-old Simba Martin; and 22-year-old Levaughn Washum-Garrison.

A fifth victim, 32-year-old Marcus Hurd, was critically wounded.

Assistant Suffolk District Attorney Edmond Zabin said Moore and Martin knew each other from prison, where they had served time together.

The shooting was the single deadliest in Boston since December 2005, when four young men were fatally shot in a makeshift basement recording studio in the Dorchester neighborhood. Two men are serving prison sentences for that shooting.