BANGOR, Maine — A pair of local shoplifters are behind bars because they not only tried to leave Sears without paying for merchandise on Saturday afternoon, but they also assaulted store employees on the way out, police say.

When Joseph Whitman Demmons, 27, of Holden sprayed a store security guard with Mace with his accomplice Brittany Holland, 20, of Hampden at his side, the misdemeanor shoplifting turned into robbery, Bangor police Sgt. Paul Edwards said Sunday.

“When you start pushing and assaulting you raise the bar to a felony,” the sergeant said. “That is kind of the lesson here.”

Demmons and Holland, who also were found in possession of the synthetic drug bath salts, both were charged with felony robbery after the 5 p.m. shoplifting spree at the Bangor Mall store and face a penalty of up to 10 years in prison and a fine of $20,000 if convicted.

Demmons has a lengthy criminal record that includes a June conviction for criminal threatening with a dangerous weapon that sent him to jail for four months, according to prior court listings printed in the Bangor Daily News.

Sears employees called police after noticing Demmons and Holland concealing items and Bangor police Officer Brian Smith was dispatched to the store. Before he arrived, one store employee was assaulted and Demmons sprayed Mace at the store’s security officer. The couple left the store and ran towards Interstate 95 and Staples.

Demmons and Holland jumped a fence — dropping stolen items as they went — and then unsuccessfully attempted to hide in the high grass. They were quickly located by Officer Dennis Townsend.

Nearly $1,000 in stolen merchandise, mostly jewelry, was found on the shoplifters or on the ground between Sears and where they were found, Edwards said.

“It was all around them,” the sergeant said. “It was strewn about from their running.”

When the two were searched for stolen merchandise, a white powdery substance believed to be bath salts was found on Holland, who is out on bail. Drug paraphernalia typically used to consume bath salts also was found, Edwards said.

Police recovered around $913 of stolen items, which was returned to the store.

In addition to the felony robbery charge, Demmons also was charged with criminal use of disabling chemicals, theft and possession of a hallucinogenic drug.

He was convicted of burglary and theft by unauthorized taking or transfer in Penobscot County Superior Court in July 2006 and sentenced to prison for four years for both, the BDN records state.

Demmons also was convicted of burglary and theft by unauthorized taking or transfer in Penobscot County Superior Court in the fall of 2005. For that conviction, he was sentenced to four years and six months behind bars, with all but seven months suspended for both charges.

He also has prior convictions for operating a vehicle while his license was suspended or revoked, operating under the influence of intoxicants, having a suspended license, refusing to submit to arrest or detention and for violating his bail conditions, according to the BDN court listings.

Holland faces charges of theft, possession of a hallucinogenic drug and violation of bail, in addition to the felony robbery charge.

She is out on bail for an offense that happened somewhere outside of Penobscot County, Edwards said. She was charged in September for violating her bail conditions by a Bangor officer but has no other Penobscot County charges, the sergeant said.

Both Demmons and Holland were taken to Penobscot County Jail and remained in jail Sunday afternoon.