Boston and Somerville police collaborated recently to arrest two individuals they believe tried to use the city’s boundaries to make their arrest and prosecution more difficult.

According to a police report, Charlestown residents had complained to Boston Police since October of drug activity going on at the Somerville/Charlestown line.

On March 12, members of the Boston Police drug control unit set up surveillance of the Pearl Street address in Somerville they had been pointed to by an anonymous tipster.

As a result of their surveillance, officers observed what they believed to be a drug deal, and then detained the parties they believed to be involved with the deal.

As officers stopped one of parties, a detective noticed that the individual made swallowing motions like the suspect might be trying to swallow drugs held in the mouth.

Seeing this, the detective “held [the person’s] head back by the jaw bone and gave verbal commands for [him or her] to spit the drugs out,” a police report said.

The suspect spit out a plastic bag that contained what officers believed to be three smaller plastic bags of crack cocaine.

Officers found the other suspect carrying a glass jar that contained a plastic bag of marijuana, two cellular phones and $12.

After being pressed, the second suspect admitted to selling drugs. Officers then asked the suspect if they would find more drugs in the suspect’s apartment.

“Yup,” the second suspect responded.

As a result of the incident, officers arrested Susan Hassan of 8 Pearl Street in Medford, Justin McDonald of 38 Grant Street in Somerville and Gardy Ferdinand of 7 Pearl Street in Somerville on drug related charges.

Due to redactions in the police report supplied to Charlestown Patch, we cannot determine what charges were applied to what suspect.