A 23-year-old Athol man was arrested Monday in connection with the murder of a young mother from Leominster whose body was found near the entrance of a wastewater treatment facility.

Keith Hamel is set to be arraigned in Orange District Court on Tuesday in connection with the death of 26-year-old Kelsey Clifford, according to a press release from the Northwestern District Attorney’s Office.

Authorities found Clifford’s body outside the facility early on Nov. 11, authorities said. Hamel’s connection to the victim, if any, is unclear.

A vigil was held Sunday for Clifford in Athol.