The entertainer, whose given name is Desmond Ballentine, was found guilty of murder by a seven member jury in the Home Circuit Court in downtown Kingston just minutes ago.
STAR sources say the entertainer left the courtroom smiling after the verdict.
The entertainer's son, Janeil, and another man, Dennis Clayton, have also been found guilty.
The three were on trial for the March 2009 murder of Ricardo Johnson also known as 'Trooper' of Marl Road in Kingston. The case, first mentioned in court in 2009, has had 17 missed trial dates and 23 mention dates in the eight years.
The prosecution called seven witnesses to prove its case against the accused in the trial which lasted one month.
One of the prosecution witnesses had reportedly testified that he saw Ninja Man at the scene of the crime and that the entertainer had fired at him.
In his defence, Ninja Man gave an unsworn statement denying that he was near Marl Road at the time of the incident.
Its understood that judge Martin Gayle wrapped up his summation shortly after 1 p.m. today, paving the way for the jury to consider the case.
The jury returned to court minutes after 4 p.m.
Earlier in the day, Ninja Man arrived at court in an ambulance, a sign that he is still feeling the effects of chest pains which caused him to be rushed to hospital midway through the trial.