SALEM – A Peabody man who admitted selling heroin to an undercover trooper three times in Lynn and once at his home in Peabody may serve up to five years in prison.Michael Morales, 21, of 4 Robin Road, pleaded guilty Monday morning in Salem Superior Court in a deal worked out by his attorney, thus avoiding a trial.Morales pleaded guilty to a reduced charge of possession with the intent to distribute heroin as well as three remaining indictments for distribution of heroin before Judge Timothy Q. Feeley.He was sentenced to serve not less than three years and not more than five years in state prison to be followed by five years of probation.The judge agreed to adopt the recommendation offered to the court by Assistant District Attorney Marsha H. Slingerland and defense lawyer Gary Zerola.The charges arise out of a three-week span that began last Aug. 25 when he made three hand-to-hand drug buys in Lynn on Standish Road, in which time the undercover trooper paid $100 to $150 for heroin.Then on the fourth heroin buy near Morales? home on Sept. 8 the trooper made a larger order of more than 14 grams of heroin for $1,500, but when the trooper arrived, Morales said he only had 7 grams with him and the rest was home.Morales instructed the trooper to drive around, come back and he would have the rest.At that point, police who were nearby doing surveillance, moved in and arrested Morales.Police then searched his home and seized the remaining heroin hidden inside a shoe in his closet.As part of the plea concession, prosecutors reduced that charge to possession with the intent to distribute heroin, sparing Morales a mandatory five years behind bars on that one charge.Zerola told Feeley that his client made a big mistake and was accepting responsibility by pleading.Morales told the judge following his confession that he exercised poor judgment and is accepting responsibility. He said he had let down his family while insisting when he gets out of prison he will become a productive member of society.Morales was indicted by an Essex County grand jury in December and has been held in custody in lieu of bail since. The judge credited him the 286 days he has spent at the Middleton Jail awaiting trial.