Alexandria Police Chief Earl Cook briefs reporters on the investigation into the Ruthanne Ladato murder.
Alexandria police released a sketch of the suspect in last week's shooting.
Alexandria Police say the same gun may have been used in three unsolved murders, potentially linking three high-profile cases.
It's been four weeks since Alexandria music teacher Ruthanne Lodato was gunned down after answering a knock at the door in the middle of the day. In a news conference on Thursday, Alexandria Police Chief Earl Cook said they are investigating the possibility that the case is linked to two other cases, both involved victims that were shot at their front door in the middle of the day.
That includes transportation planner Ron Kirby and the murder of real estate agent Nancy Dunning, who was the wife of the former sheriff, in 2003.
"These cases will be investigated as a series of crimes," Cook said.
Cook says the crime scene analysis shows that the bullets recovered from the Lodato case have the same rifling and characteristics as bullets in the Kirby and Dunning case, although the link was not conclusive.
The FBI and the Virginia State Police are helping with the investigation, and authorities have released a composite image of an older white male with a balding head, gray hair and a full beard.