BALTIMORE (WJZ)– Police make an arrest in the murder of a 12-year-old Gaithersburg girl.

Monique Griego has the latest on the family member now behind bars.

Investigators say David Hang, 42, stabbed his stepdaughter to death. And they told WJZ it was DNA that linked him to the case.

It’s a crime that rocked a Gaithersburg community. Back in May, Jessica Nguyen, 12, was found stabbed to death inside her family’s townhouse on Raven Avenue.

“We were upset and angry because we weren’t told anything,” said Scott Sharpneck, Hang’s neighbor.

Neighbors like Sharpneck waited months for an arrest. Then this week, there was a break.

Montgomery County Police arrested David Rich Hang– Nguyen’s stepfather– for her murder.

“Evidence was discovered that led detectives to Mr. Hang,” Officer Howard Hursch of the Montgomery County Police Department said.

Investigators say DNA found on a knife sheath and bootprints at the scene linked Hang to the murder. They say at the time, Hang no longer lived at the home. But it’s been reported, he and Nguyen’s mother were going through a messy divorce.

“We don’t know the specifics of the divorce,” Hursch said. “However, we do know that Hang is also married to another woman.”

Because there was no forced entry, police first focused on family members and others who may have had access to the house.

“Through a process of elimination, by checking those who had access to the home, detectives were able to narrow down their search,” Hursch said.

Sharpneck says most neighbors believed Nguyen was killed by someone who knew her. Still, that didn’t make the news any easier for him to take.

“How someone that you rely on, someone that’s close to you, could really do that to you,” he said. “It just doesn’t make any sense.”

Neighbors said the family has since moved from that townhouse. As for Hang, he is currently in jail without bond.