PEPPERELL — Police arrested two people last week whom they say were connected to a large-scale firearms theft and located 16 weapons, including several semi-automatic rifles, in a Pepperell home, authorities said.

Wayne Shay, 36, of Nashua, and Sheri Napier, 36, of Dracut, were arrested, according to Massachusetts State Police. They face charges as fugitives from justice on New Hampshire arrest warrants, and Massachusetts authorities expect to file additional charges.

The investigation began following a theft of firearms — police did not list a date, but described it as “recent” — in Nashua, New Hampshire. On Thursday, State Police began searching for two suspects linked to the incident and located a Nissan Altima allegedly used by the suspects outside a Dracut residence.

After conducting surveillance on the home and receiving information that the suspects were in the home asleep, officers arrested both Shay and Napier without incident, according to the press release.

Further investigation by both Nashua police and Massachusetts State Police led authorities to 21 Townsend St. in Pepperell, where they allegedly found “16 stolen firearms, 17 high-capacity magazines, a 100-round drum magazine and more than 1,000 rounds of ammunition,” the release stated. The arsenal included three AR-15-style rifles, two AK-47-style rifles, four other semi-automatic rifles and multiple pistols, police said.

(Shay and Napier were to be arraigned in Ayer District Court, after the Voice’s deadline.)

A man and a woman standing on the stoop of 21 Townsend St. on Friday afternoon declined to comment. The residence is one of several addresses in a multi-unit building off a busy road in Pepperell.

The investigation was a joint effort between state police, local departments in Nashua and Dracut and the Middlesex County District Attorney’s office.

Early last month, the State Police Gang Unit seized 58 guns and dozens of illegal homemade silencers from a Shirley home. A lawyer for the suspect, Jeffrey Dusti, argued in court that the guns were a legal collection.

Dusti, 62, faces over 100 criminal firearm charges following the seizure.

Reporter Elizabeth Dobbins contributed to this story. Follow Chris on Twitter @ChrisLisinski.