Jason Thomas Scott, the Largo man charged in a brutal double-murder and suspected in other killings, considered fleeing the country after he was charged with breaking into a gun store in the summer of 2009, according to testimony in Scott’s trial in federal court in Greenbelt.

Marcus D. Hunter, 25, testified Wednesday that he committed dozens of break-ins and six or seven armed home invasions with Scott, 28. Hunter has pleaded guilty to illegal possession of a firearm and illegal possession of a silencer, and agreed to testify for the government in the hopes of gaining leniency at sentencing

In the summer of 2009, after he and Scott were arrested on federal firearms offenses, Hunter testified that he created a Facebook account using the name “Jack Napier.” Hunter said that was an “alter ego” of the comic book character The Joker. (In the 1989 movie “Batman,” Jack Napier is the name of a hoodlum who becomes The Joker after being dropped in a vat of chemicals).

Scott, meanwhile, created a Facebook account using the name “Alexander Richardson,” Hunter said.

Federal prosecutors displayed Facebook messages exchanged by “Napier” and “Richardson”in August, 2009. At the time, Scott was charged with stealing and trying to sell firearms. He had not yet been charged in the burglaries, home invasions, or the murders. Neither Scott nor Hunter were detained at the time.

In one Facebook message, Hunter expressed incredulity that Scott was facing multiple charges: “I MEAN, UR THE MAN. WHAT EVIDENCE DO THEY HAVE . . . AND DO U HAVE YOUR CAR YET?”

Scott responded: “ATF took my car. They are keeping it. They are going to sell it. I’m mad.”

In another message, Scott mused about leaving the country: “No (expletive). Mexico, New Zealand, or Canada. Pick one.”

Nearly a year later, in July 2010, a Prince George’s grand jury indicted Scott on two counts of murder and other offenses. The grand jury accused Scott of murdering Delores Dewitt, 42, and her daughter Ebony, 20. Their bodies were found inside a burning, stolen car in Largo on March 16, 2009.

Scott is scheduled to be tried for those murders in Circuit Court in Upper Marlboro in November. Assistant State’s Attorney Wesley Adams, who is prosecuting Scott for the murders, watched Hunter testify Wednesday. Hunter concluded his testimony Thursday.

Prince George’s police have said Scott is also a “person of interest” in the double-murder of another mother and daughter from Largo. On Jan. 26, 2009, the bodies of Karen Lofton, 45 , and her daughter Karissa, 16, were found inside their locked home. Both had been shot to death.

Police have also said they are investigating whether Scott committed a 2008 murder in which a Bowie woman was shot to death inside her home, which was then set on fire.

An agent with the federal Bureau of Alcohol, Tobacco & Firearms testified earlier in the trial that Scott admitted committing about 30 break-ins.

Hunter testified that he became a partner in crime with Scott in 2007. Initially, he and Scott burglarized unoccupied homes, Hunter testified. Eventually, Scott persuaded him to brandish guns and invade homes that were occupied, Hunter testified. Scott believed they would get more money that way, Hunter said.

Hunter estimated that he committed 30 to 40 crimes with Scott; most were burglaries, six or seven were home invasions, Hunter said. Hunter testified that he worked with Scott at the UPS facility in Largo, where both were clerks.

Hunter said he split the take from the crimes with Scott. Hunter said all the crimes netted him about $3,000 in cash. He said he and Scott also took TVs, electronic gaming systems, computers, and jewelry.

He and Scott sometimes went to an unoccupied home off Route 202 in Upper Marlboro to divide their loot, Hunter said. Hunter called the home the “Spooky House.”

In the summer of 2009, Hunter said, he and Scott broke into a Carroll County gun shop and made off with handguns, assault rifles, shotguns, and a large amount of ammunition.

Hunter testified that he and Scott planned on selling the stolen firearms, but were arrested shortly after they sold weapons to a law enforcement informant.

Scott’s defense attorney, Kobie Flowers, said in his opening statement that his client is guilty of stealing the firearms and trying to sell them, but innocent of the other offenses. Flowers said Scott admitted to investigators that he committed 28 burglaries and nine home invasions because he was struggling with his identity as a gay man. Scott exaggerated his crimes to try to fit in, Flowers said.

The trial is expected to conclude with closing arguments early next week.