BANGOR – The retrial of a man accused of using a Molotov cocktail to start a fire that destroyed a downtown business began Monday.

Scott Gagnon, 19, and Harold Hawkes, 19, both of Bangor, were charged with Class A arson in connection with the April 4 fire that destroyed The Extra Touch lingerie shop. Upper floors in the six-story building at 29 State St. were heavily damaged.

Gagnon’s first trial ended in a mistrial Dec. 14 when the Superior Court jury could not reach a verdict. During that trial, Hawkes invoked his Fifth Amendment protection against self-incrimination and did not testify against Gagnon.

Last month, Hawkes pleaded guilty to the charge and was sentenced to five years in prison.

The prosecution claimed that Hawkes prepared a Molotov cocktail that Gagnon tossed through a window of The Extra Touch about 4 a.m. April 4. Shop owner Paula Anderson told investigators last year that she had had a confrontation with Hawkes a week or two before the fire about her suspicions that he and his friends were shoplifting from her store.

A Penobscot County jury heard opening statements Monday and the testimony of one witness before Justice Andrew Mead adjourned for the day. The trial was expected to resume today with testimony from the State Fire Marshal’s Office and Bangor police officers, according to Deputy District Attorney Michael Roberts.

John Donovan, who manages the building for Coe Management Group, testified Monday that damage from the blaze totaled $790,000, according to Roberts. While other tenants returned to offices after renovations were made, The Extra Touch is not expected to reopen, he has said.

Roberts refused to say whether Hawkes would testify against Gagnon.

Defense attorney Jeffrey Silverstein of Bangor, however, confirmed Monday that Hawkes is on the prosecution’s witness list.

“Hawkes has been named as a witness and I think they will call him,” Silverstein said.

In opening statements, both lawyers laid out strategies nearly identical to those used in Gagnon’s first trial.

Roberts argued then that Gagnon confessed to setting the fire, while defense attorney Silverstein told the jury Gagnon’s statement was coerced.

“The last trial was tough,” said Silverstein on Monday afternoon. “This one will be tough, too.”