Members of the District 1 Drug Control Unit observed a posting on an Internet site where an individual was selling drugs. Yesterday at 2:15pm, an officer called the suspect and made arrangements to purchase cocaine. At about 8:50pm last night, the suspect called the officer and told the officer to meet him outside of One Center Plaza. The suspect described himself and the vehicle he would be in. Officers responded to the area and the undercover officer entered the vehicle and completed the drug transaction. The undercover officer exited the vehicle and signaled to other officers that the deal had been completed.The suspect drove away and was stopped in front of the District 1 police station. Officers arrested Tyrone Burgo, 20, of Brockton and charged him with Distribution of Class B, Distribution of Class B within 100” of a playground, and various violations of the auto laws. Burgo will be arraigned in Boston Municipal Court on Monday morning.