PROVIDENCE, R.I. (AP) — The Rhode Island State Police have joined the investigation into suspect nomination signatures submitted by the campaign of Lt. Gov. Sabina Matos, a candidate for the U.S. House seat vacated by former Democratic Rep. David Cicilline.

Election officials in three communities located in the 1st Congressional District this week asked local police departments to investigate suspected fraudulent signatures on nomination papers submitted by the Matos campaign.

Matos is one of 12 Democrats hoping to succeed Cicilline, who stepped down earlier this summer to become the president and CEO of the Rhode Island Foundation.

Attorney General Peter Neronha’s office is helping lead the investigation. Neronha has said his office would examine the nomination forms the Matos campaign submitted in every municipality in the district.

Matos campaign manager Brexton Isaacs issued a statement Thursday stating that Matos is “deeply disappointed and angry” over the signatures.

The investigation is focused in part on part-time field campaign workers who gathered and submitted the signatures for Matos.

Isaacs said the campaign provided clear instructions on how to correctly gather signatures.

“Anyone who violated these detailed instructions and the nomination process has no place in our campaign and will be held accountable,” Isaacs said.

The special primary election will be held on Sept. 5. The special general election will be held on Nov. 7.