SALEM – A Peabody man who admitted being involved in the sale of cocaine in 2009 is headed to state prison for three years and then will be deported back to his native country, the Dominican Republic.Edison Carrasco. 21, last lived at 20 Harris St., #2, Peabody, changed his plea from not guilty to guilty Friday afternoon in Salem Superior Court to two counts of trafficking over 14 grams of cocaine.Judge John T. Lu agreed to sentence him in accordance with an agreement reached by Assistant District Attorney James P. Gubitose and defense lawyer Joseph F. Collins.Carrasco was arrested Dec. 10, 2009 following an investigation by Peabody police detectives, State and Boston police.After receiving information, police following his alleged co-conspirator, Hansel Martinez, 37, of Allston, from Lawrence into Beverly where he allegedly completed a drug deal.From there he was followed to 10 Harris St., the apartment of Carrasco which is believed to be a stash house.Authorities arrested the pair when they saw them leave the apartment.Police executed a search a few hours later and reportedly discovered 280 grams, over one-quarter of a kilo of cocaine, along with other drug related items. The estimated street value of the cocaine is $20,000, police said.Gubitose maintains that Martinez is the main target in the case.He currently is held in lieu of bail pending the outcome of his case.Collins pointed out to the judge that Carrasco has no prior record and comes from a good family as he urged the judge to adopt the joint sentence.The judge credited Carrasco the 422 days he has spent in jail in lieu of bail awaiting trial on the case.