SALEM – A Lynn kitchen worker who admitted selling heroin to undercover police four times over a 3-week span last winter will spend up to five years in prison before being placed on probation.In Salem Superior Court Monday morning, Ruben O. Ramos, 20, of 158 Chestnut St. #3R, avoided a trial by pleading guilty to four counts of distribution of heroin as well as distribution of cocaine and possession of marijuana.He will serve three-to-five years in state prison before being placed on probation for another five years.Judge Howard J. Whitehead sentenced Ramos in accordance with the agreement reached by Assistant District Attorney Kim M. Faitella and defense lawyer Randi Potash.Faitella told Whitehead that the incidents involved a series of transactions that began on Jan. 24 after police received information that a man using the street name “Le Fe,” was selling drugs in the Lynn area.An undercover officer contacted the man, later identified as Ramos and a meet was negotiated on Jan. 24 where two bags of heroin containing one-half gram was sold for $100 inside a Union Street pizza shop.Then four days later, Jan. 28 one-half gram was sold for $50 in front of a Mall Street home and on Feb. 8 heroin and cocaine was negotiated for $90 at the corner of Mall Street and Western Avenue.Finally on the afternoon of Feb. 13 two fingers (the cut off fingers of surgical gloves used to package heroin) was sold for $1,600 again at the corner of Mall Street and Western Avenue.When Lynn Drug Task Force members moved in to arrest Ramos they seized the cell phone which helped set up the deals and location along with a quantity of marijuana and the $1,600 in marked bills found in his pocket.As part of the plea negotiations, the indictment was reduced to distribution of heroin, sparing him of a minimum mandatory 5-year prison term on that one indictment.Under the terms of his probationary period, Ramos is to get his general equivalency degree (GED), refrain from all alcohol and drugs, consent to random screenings, be evaluated for drug treatment and counseling as deemed necessary or remain employed or actively seeking a job.