(CNN) — It has been one month since Hannah Graham, a student at the University of Virginia, was last seen and her parents are asking for help.
“It is heartbreaking for us that the person or persons who know where Hannah is have not come forward with that information. It is within their power both to end this nightmare for all,” Hannah’s parents, John and Sue Graham, said Monday.
For the better part of the last month, Mark Eggeman from the Virginia Department of Emergency Management has helped orchestrate the largest missing person search in the atate of Virginia’s history.
“The search for Hannah is currently in a transition stage,” Eggeman said on Friday.
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The city of Charlottesville will be in charge as of Monday, taking over from the Department of Emergency Management, with a different focus and change in strategy.
Eggeman said experts are still investigating tips and leads and are analyzing some imaging analysis taken from a specialized camera mounted onboard a private plane. The plane was donated to the search effort from Woolpert Inc.
The design and geospatial company based out of Ohio donated its plane with an ultra-high precision sensor to scan “areas of interest” that were requested by law enforcement. The scanning is “positionally accurate,” Senior Vice President Shane Imwalle said, which can be a great help to law enforcement.
While the search for Graham is paramount for the Charlottesville Police Department, solving the abduction and murder of Morgan Harrington, a Virginia Tech student who went missing in October 2009, is a priority for the Virginia State Police.
A law enforcement source tells CNN that foreign DNA in the Harrington case provides a forensic link to Jesse Matthew, who has been charged with abduction with the intent to defile in Graham’s disappearance.
Local Yellow Cab owner Mark Brown said his cabbies who knew Matthew say he was driving a cab the night Harrington went missing. Matthew held a taxi cab license in the city of Charlottesville from 2005 to 2010. A source close to the case confirmed that police recently impounded the cab Matthew was allegedly driving the night Harrington disappeared.
The Virginia State Police said they “will release new information at a time and in a manner that does not jeopardize the integrity of this ongoing, complex criminal investigation.”
As the investigation into both cases continues, so does the search for Graham.
In the early morning hours of September 13, several surveillance cameras in the Charlottesville downtown mall area showed Graham leaving the Tempo Bar at around 2 a.m.
The cameras also showed a man, later identified as Matthew, following her. Matthew is believed to be the last person who saw Graham alive. A warrant for his arrest was issued and authorities later found Matthew 1,300 miles away camping on a beach in Galveston Texas.
The 32-year-old Matthew was returned to Virginia and charged. His next court hearing is scheduled for December 4.
Mathew’s attorney did not respond to CNN’s request for comment.
“Again, we would like to urge anyone who has not already searched their property in the city of Charlottesville, or any of the neighboring counties, to please do so today. Please, please, please help us to bring Hannah home,” John and Sue Graham said in Monday’s statement.
Authorities are offering a $100,000 reward for information leading to the safe return of Graham, 18, who was a second-year student at the university.