Four people, including 22-year-old Marcus Gomes of Onset, were arrested on drug trafficking charges Wednesday night after police followed them from Hyannis to Boston and back to Wareham.

According to a Wareham Police Department report, for the past month the Barnstable Police Department Narcotics Unit has been investigating 29-year-old Candace Johnson of East Sandwich for allegedly distributing cocaine in Hyannis.

From their investigation, police came to believe that Johnson was making frequent trips to Wareham and Boston to get cocaine.

On Wednesday, police followed Johnson to Wareham, where she picked up Johnathan Depina, 25, of Dorchester. Depina was dropped off by Gomes and Charles Dejesus, 23, of Wrenthem, in Gomes' car.

According to the report, police followed Depina, Johnson and their driver to Inwood Street in Dorchester, where Depina was dropped off. Johnson and the driver of the vehicle waited in a nearby parking lot.

About five minutes after Depina was dropped off, Gomes and Dejesus arrived on the same street in Dorchester in Gomes' car, circling the block inspecting other vehicles.

"Using a separate counter surveillance vehicle is a common tactic that sophisticated drug traffickers use to determine if law enforcement is present," Wareham detective William deSilva wrote in his report.

Gomes, Dejesus, and Depina exited the same Inwood Street residence together and Depina was then taken to Johnson's vehicle by a different car, according to the report.

Johnson and Gomes' vehicles traveled back to Wareham where they were stopped by Wareham and Barnstable detectives.

Both Johnson and Depina were allegedly in possession of 32 grams of cocaine each, according to the report. Both were charged with trafficking cocaine and conspiracy to violate drug laws.

Detectives seized approximately 12 grams of cocaine and about $1,480 from Dejesus and found Gomes in possession of $5600. Both were charged with possession of cocaine with intent to distribute and conspiracy to violate drug laws.

Gomes was arrested after a traffic stop on Feb. 3 and was charged with possession of a loaded firearm without a permit, possession of ammunition without a permit, disorderly conduct, resisting arrest and assault and battery on a police office.

It is unclear whether Gomes posted bail or was released under his own personal recognizance after his Feb. 3 arrest.

All four were arraigned Thursday in Wareham District Court.