REVERE-An undercover police operation netted four arrests Thursday into Friday and possibly a fifth on the way for cocaine distribution charges.Khary T. Barrow, 28, of 250 Broadway, Revere, Tyler Brown, 28, of 36 Hazleton St., Mattapan, Samuel E. Falcon, 37, of 27 Wave Ave., Revere and Matthew J. Hoppe, 21, of 250 Broadway, Revere were all arrested on a variety of drug charges.Police say the arrests were made after an undercover State Police officer made three purchases of cocaine from a 37-year-old Revere woman.The woman has not been arrested, but Revere Police Capt. Michael Murphy says she will likely face cocaine distribution charges. The charges might come in the form of a warrant or an indictment, he said.Murphy says the three drug transactions took place inside the woman’s apartment at 250 Broadway.On one occasion, the undercover officer met the woman at 250 Broadway to purchase “a large quantity of cocaine,” Murphy said. From there, they allegedly traveled to a home on Dolphin Avenue in Revere where the woman allegedly went inside as the undercover officer waited in the car.When the woman returned, she allegedly instructed the officer to drive to an undisclosed location to obtain the drugs. They were pulled over by other police officers as they drove to the location, police said.As a result of the investigation, police obtained and carried out search warrants at the Dolphin Avenue address and a Wave Avenue address, police said.Currently, Falcon is facing two counts of trafficking cocaine and conspiracy to violate drug laws.Barrow is charged with possession of crack cocaine with intent to distribute, a drug violation in a school zone and an outstanding warrant.Hoppe and Brown are charged with distribution of cocaine, a drug violation in a school zone and conspiracy to violate drug laws.