Updated at 8:45 p.m. with the Boston officer's name

Dedham Police arrested a 23-year-old Boston man Monday evening after he allegedly attempted to rob Tedeschi in Oakdale Square.

An off-duty Boston Police officer told Dedham Police that he saw Sean Ryan-Fallon wearing a hooded sweatshirt drawn over his face and gloves on his hands. The officer said Ryan-Fallon was acting suspiciously as he entered the store, according to a Dedham Police statement.

Boston Police detective Mike Kane was leaving the conveinence store when he said he noticed Ryan-Fallon pass by him.

Dedham Police were notified, and while en route to Oakdale Square, Kane went into the store and said Ryan-Fallon was behind the register with an undisclosed amount of money and a knife in his waistband, according to a Boston Police statement.

Kane then drew his gun and ordered Ryan-Fallon to drop the weapon, Boston Police stated.

By the time Dedham Police arrived, Kane had the suspect in custody, according to police reports.

Ryan-Fallon is charged with armed robbery.