STANDISH – Detectives investigating last month’s report of an armed robbery and arson at Sebago Village Variety concluded Tuesday that the store manager set the fire and concocted the report that she had been robbed.

Rebecca Lavallee, 28, of Topsham, was arrested at the store on charges of arson and filing a false public report, the Cumberland County Sheriff’s Department said.

Lavallee told investigators she was locked in a back room while the robber tried to set fire to the building on the morning of Nov. 29.

She was rescued minutes after the county dispatch center received a call about an alarm at the store. Deputy James Estabrook, who was patrolling the area, found Lavallee screaming and pounding in the locked storage area while a fire was burning in the office and another fire was smoldering in the hall.

The Standish fire department arrived a few minutes later and put out the flames. Lavallee did not require medical attention.

The thief was reported to have stolen several hundred dollars.

Chief Deputy Richard Gagliano said the sheriff’s office hopes that Lavallee’s arrest eases any fear arising in the community from the incident.

Gagliano would not speculate on what might have motivated Lavallee to set a fire that could have put her at risk.

Lavallee was being held at the county jail, where bail was being set in advance of her arraignment in District Court.