Jones now is being tried for second-degree murder and other charges in connection with the shooting.
A summary of the prosecution's case presented Monday during opening statements virtually was the same as the case presented in 2005.
Assistant State's Attorney Viki Pauler said Jones shot and killed Dennis, who was 19 at the time, outside of a party at Washington Gardens apartments in the early morning hours of March 14, 2004.
Pauler said a bullet in Dennis' body matched a .22-caliber handgun found in Antietam Creek near where police found Jones hiding after a 2005 assault at Weis Market on Eastern Boulevard.
During the first trial, prosecutors played a taped statement in which Jones admitted to firing a .22-caliber pistol "in the air" near the courtyard.
That tape was not played Monday for members of the jury, who do not know about the first trial, but likely will be played today when the trial resumes.
Witnesses testified Monday that Dennis and others had gone from the party to the courtyard on the morning of the shooting after their friend, Andrew Snyder, who was 13 at the time, returned to the apartment saying he had been robbed.
Several shots were fired at the group from a walkway near the corner of the courtyard, according to witnesses.
Witnesses who testified Monday said they could not identify the shooters, but could see a group of people in the shadows across the courtyard.
Police and crime scene investigators found shell casings and live rounds from .380-caliber and .22-caliber handguns in the courtyard.
Witnesses also described an altercation earlier in the night when a man named Azaniah Blankumsee disrupted the party. Blankumsee had pulled a .380-caliber pistol and been kicked out by the party's host, according to witnesses.
Defense Attorney Alan L. Wink kept his cross-examinations short, asking witnesses if they had seen Jones at any time during the incident. None said they had.
Prosecutors spent most of Monday afternoon questioning forensic scientist Jeffrey Kercheval and logging evidence he collected at the crime scene both the morning of the shooting and the next day.
Prosecutors also called Dennis' mother, Vanessa Dennis, to the stand. She said little, but sobbed when shown photos of her dead son, saying the last time she saw him, he was at home "eating a bowl of Froot Loops."
The trial is expected to conclude today.