LYNN – A judge ordered $20,000 cash bail for a city man charged with trafficking heroin who is currently in jail on previous drug charges.David Estrada-Pagan, 30, of 71 Harwood St. #12, pleaded not guilty Wednesday in Lynn District Court to charges of trafficking in heroin; and possession with intent to distribute Class B drugs.Attorneys said Estrada-Pagan is currently one month into serving a four-month sentence after pleading out on a 2009 drug case from Lynn.The new charges stem from an undercover investigation in which a confidential informant told police a man known as “Antonio” was selling heroin out of the Harwood Street address, Essex Assistant District Attorney Justin Edwards told the court.Police reported organizing two undercover buys using the confidential informant.Edwards said the first buy happened inside the defendant’s apartment while the second buy occurred on the street and was watched by police.Police executed a search warrant at the apartment on June 17 and found a Lowell man who said the apartment belonged to his friend “David,” Lynn Police Officer Ross Panacopoulos wrote in a report. Panacopoulos also noted police saw a small packet of suspected heroin sitting on a table and next to a bail slip.Police reported finding more bags of suspected drugs, recovering a total of 22.5 grams of suspected heroin and 12 grams of suspected cocaine from the apartment. Police also reported finding digital scales, chemicals commonly used to cut drugs, a notebook “with entries consistent with drug sales” and a Massachusetts driver’s license belonging to Estrada-Pagan. Police identified the person shown on the license as the “Antonio” officers had watched during the second undercover buy. Police also arrested and charged the friend, David Reyes, of Lawrence, with heroin trafficking and possession with intent to distribute Class B drugs.Edwards requested Estrada-Pagan be held on $100,000 cash bail.But court-appointed defense attorney Barbara Keon said her client says he only uses the bedroom of the apartment. She noted the only thing police reported finding in that room was an expired license.”He is not responsible for other roommates and what they do,” Keon told the court.She said the replica guns were toy guns that belonged to her client’s young son.Keon requested $1,500 cash bail, which she said was the most her client could pay after completing his current sentence.Judge Ellen Flatley ordered the defendant held on $20,000 cash bail following the completion of his sentence. Estrada-Pagan is scheduled to return to court Aug. 14.