MONROE-Since the beginning of last September, Monroe Police have arrested four people for selling drugs and charged 17 others with possession. The drugs were being sold to mostly young people in their late teens to early 20s. In addition to powdered cocaine and marijuana, police also have confiscated Ecstasy, the amphetamine-based designer drug. Several of the people who have been arrested are now working with police as their undercover efforts continue. The investigation began after police received information that a 19-year-old Fitzgerald Court man was selling cocaine, said Police Chief Dominic Giudice. That young man was arrested on Sept. 9 and charged with two counts of third-degree criminal sale of a controlled substance and two counts of criminal possession of a controlled substance, both felonies. A little more than a month later, police arrested a 23-year-old woman from Newburgh who, they said, was selling cocaine in Monroe. On Oct. 19, she was charged with two counts of third-degree criminal sale of a controlled substance and two counts of third-degree criminal possession of a controlled substance. Working in conjunction with the Orange County Sheriff's Narcotic Unit, Monroe police continued their investigation. On Jan. 18, a 26-year-old man was arrested on a warrant, charging him with fifth-degree sale of marijuana. Guidice said he sold marijuana to undercover police officers at the James Motel. The fourth alleged dealer, a 19-year-old man from Hillside Terrace, was arrested Feb. 1 and charged with three counts of criminal possession of controlled substance and three counts of criminal sale of controlled substance, both felonies. In addition, Guidice said, Monroe police have arrested six others on a charge of seventh-degree criminal possession of a controlled substance and another 11 on marijuana possession charges.