Three years into the investigation of the fatal shooting of Darien Richardson, Portland police say the so-called gun show loophole has cut short one of their investigative leads.

Police Chief Michael Sauschuck said Monday that holding private sellers to the same standard as gun shops for background checks and record-keeping would make it possible to track a gun from one owner to another, which could be crucial in a murder case.

The trail of the gun that was used to shoot Richardson went cold after the gun was sold by its last known owner at a gun show, with no record of the sale.

Richardson, 25, was shot in a leg and a hand on Jan. 8, 2010, as she lay asleep with her boyfriend in her apartment on Rackleff Street.

She was released from the hospital after 20 days, but died a month later from a blood clot that a medical examiner determined came from one of the gunshot wounds.

One of the biggest breaks in the case came when a forensic examination showed that the .45-caliber semiautomatic pistol that Daudoit Butsitsi used to murder Serge Mulongo on Feb. 10, 2010, was the gun that had been used to shoot Richardson a month earlier.

Butsitsi, who is serving a 38-year prison term, has refused to say where he got the gun.

Portland detectives worked with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives to track down the manufacturer, the distributor and the gun shop that sold the gun.

Police hoped that by tracing the trail of ownership, they could get a lead on who Butsitsi got the gun from and who might have shot Richardson.

They found the legal owner of record but then hit a dead end. The owner told police that he sold the gun at a gun show and had no record of who bought it.

“You have a weapon that’s been used in two homicides in the city of Portland, as safe as the city is and as safe as the state is, that falls smack in the middle of the gun show loophole debate,” Sauschuck said Monday.

Sauschuck said that anyone who gets turned down at an authorized gun shop can go to a gun show or a classified advertiser like Uncle Henry’s and buy a gun without any background check.

If everyone had to get a background check to buy a gun, investigators would have a valuable tool in tracing how a gun gets into the hands of a criminal, he said.

He said there still could be gaps, like when guns are stolen, but police would at least have a lead, and it would be harder for a convicted criminal to get a gun.

Police say they are still aggressively investigating Richardson’s death, and her parents have offered a $10,000 reward for information leading to an arrest.

Police say they believe the attack was related to the illicit sale of OxyContin and have been working with the Maine Drug Enforcement Agency. They say there’s no suggestion that Richardson was involved in drug trafficking.

Police say her boyfriend, Cory Girard, has been interviewed several times but denies knowing who the shooters were.

“We are continually trying to put the pieces together,” said Lt. Scott Pelletier, head of the Portland Police Department’s criminal investigations division.

Staff Writer David Hench can be contacted at 791-6327 or at:

dhench@pressherald.com