A MS-13 gang member and four illegal immigrants are in custody after Barnstable Police and two US government agencies investigated potential gang activity in the Fresh Holes neighborhood in Hyannis, police said. 

US Immigration and Customs Enforcement (ICE) and Enforcement and Removal Operations (ERO) along with BPD completed a two-week investigation resulting in a warrant for the detention of four men by ERO and a warrant arrest on a individual accused of assault, police said.

According to the FBI, MS-13 (Mara Salvatrucha) is the most dangerous gang in the US. The gang is mostly Salvadoran nationals or first generation Salvadoran-Americans, but also includes other South and Central American immigrants. MS-13 is known for its penchant for violent crimes from assaults, homicides to using blunt objects like machetes to injure victims.

Martir Lemus, 28, of El Salvador was taken into custody by the Barnstable Police Department on an arrest warrant by Somerville District Court for assault and battery by a dangerous weapon. Lemus is a confirmed member of the MS-13 gang. He will be arraigned in Barnstable District Court for his charges in Somerville. Police are also holding Lemus on a ICE ERO detainer, police said.