LYNN – A judge ordered a city teen held without bail on a murder charge after police said gunshot residue from a weapon used in a Jan. 12 fatal shooting – a gun the defendant has been charged with carrying while fleeing the scene – was found on the teen’s clothing.But a public defender said at least two guns were used in the shooting and suggested another explanation for the gunshot residue.”There is not a lot of proof to the gunshot residue other than (the defendant) may have been near to, or have been holding, a gun at some point or have been next to someone who may be the shooter,” public defender Rebecca Whitehill said Thursday in Lynn District Court.Jacquan McKenzie, 18, of Lynn, was arrested Wednesday night on a warrant for the murder of Hery Aquino, 29.McKenzie was arraigned on the charge Thursday in Lynn District Court where a plea of not guilty was entered on his behalf. He is being held at Essex County House of Correction in Middleton.Police responded to the Curwin Circle housing project at approximately 1:30 p.m. Jan. 12 and found Aquino with a gunshot wound to the head. Aquino died later that night.Police said witnesses described a suspect in a blue sweatshirt fleeing the scene, and officers caught up with the suspect, later identified as McKenzie, after a chase through Holyoke Street backyards. Officers also recovered the sweatshirt and a .45-caliber gun McKenzie is alleged to have dropped during the chase.McKenzie was held without bail and then on $5,000 cash bail after his Jan. 13 arraignment in Lynn District Court on charges of carrying a firearm without a license; carrying a loaded firearm without a license; carrying a firearm with an obliterated serial number; and trespassing.McKenzie was indicted and was arraigned Feb. 28 in Salem Superior Court on charges of carrying a firearm without a license; carrying a loaded firearm without a license; and defacing the serial number of a firearm.At the time, McKenzie had been on a GPS-monitored lockdown in Peabody, and prosecutors did not seek additional bail at the Superior Court arraignment, according to court records.McKenzie was arrested on a warrant for murder Wednesday night and pleaded not guilty to the charge Thursday in Lynn District Court.Prosecutor A.J. Camelio and Whitehill each provided additional details about the investigation during the Thursday arraignment.Citing a State Police Statement of Facts by Trooper Steven Buccheri, Camelio said police at the murder scene recovered several shell casings and bullets from the gun McKenzie is alleged to have been carrying.One of the recovered bullets also tested positive for blood, Camelio said.The blue sweater/sweatshirt officers and witnesses saw McKenzie wearing and McKenzie’s pants also had gunshot residue, according to the statement by police.Camelio also said a witness reported seeing McKenzie shoot Aquino.Camelio requested McKenzie be held without bail.Whitehill said the witness who allegedly observed the shooting was “somewhat suspect,” however.Whitehill said the witness only went to police after seeing McKenzie’s picture in the newspaper and there were “out-and-out lies” in what the witness told officers.Moreover, Whitehill said the witness only knew about two guns being involved in the shooting (police at the murder scene recovered evidence from a .45-caliber and a 9-mm gun) after the witness was pressured by police.Court documents do detail the witness’ interview with police. Buccheri’s statement says a witness told police a friend of Aquino’s had shot back at the suspect who fired at the deceased.Whitehill noted McKenzie has been complying with conditions of release since posting bail, and she requested an additional $100 or $1,000 cash bail if necessary.(Whitehill also questioned why police allegedly broke down doors in arresting McKenzie if the defendant’s location was being monitored by GPS.)Judge Ellen Flatley ordered McKenzie held without bail without prejudice, which means that attorneys can argue