Mystic — “It’s about Gracie and Chase.”

Those were the words of Herndon, Va., police Lt. Jim Moore Wednesday afternoon after he and Detective Michael Croson had driven seven hours to turn over the purple peace sign stolen from the playground behind the Ocean Community YMCA that is dedicated to Grace McDonnell, one of the children killed in the Sandy Hook massacre.

A second sign had been taken from a playground in Mantoloking, N.J., dedicated in memory of Chase Kowalski, another child killed at Sandy Hook Elementary School in 2012.

After Grace’s sign was taken on May 6, Stonington Detective Sgt. David Knowles conducted a computer-based investigation and was able to identify the address of the man now charged with stealing signs from two playgrounds dedicated to Sandy Hook victims.

After identifying the address on the afternoon of May 27, Knowles alerted Herndon police early the next morning. They quickly obtained a search warrant for the residence of Andrew Truelove, 28, and recovered the signs on May 30. Truelove admitted during questioning to taking the signs, according to Herndon police.

“This is not about the Herndon or Stonington police department. It’s about Gracie and Chase and that’s why we’re here,” Moore said during a press conference in front of the Stonington Police Department, where the two signs were on display.

Knowles, who hugged Moore and Croson when he met them for the first time Wednesday, said the investigation was the best example of cooperation between police departments and the media to solve a case that he’s seen in his 28 years as an officer.

Knowles said it was a great feeling to play a role in recovering the signs and to be able “to say to everybody, we got the signs.”

Stonington Police Chief J. Darren Stewart said hundreds of people volunteered to help build the playground, which opened April 27, and everyone was saddened by another senseless act when the sign was stolen. He said Knowles, who heads the department’s detective division, was “all over the case from day one and was determined to solve it.”

He said the identification and arrest of Truelove and the return of the signs were the result of good old-fashioned police work, computer technology and “help from our new friends in Herndon, Virginia.”

Because the sign was replaced at the playground last week, the recovered signs will be given to the parents of Grace and Chase, according to Stonington police Capt. Jerry Desmond.

He said it was important to not only police but the communities involved to solve the case and support the memorial efforts to honor the victims of Sandy Hook.

Desmond added that the investigation remains open. It will be up to the New London County state’s attorney office to pursue larceny charges against Truelove and decide whether to extradite him from Virginia, where he has been held on charges in unrelated cases since May 26 — four days before the search of his home uncovered the signs.

After the theft, someone claiming to have taken the sign called McDonnell’s mother and called the shooting at Sandy Hook a hoax. Earlier this month, Moore said photos of the stolen signs along with a “disturbing rant” surfaced on the website thedailybanter.com, a response to writer Chez Pazienza’s column condemning the theft in Mystic. The author claimed to have stolen the signs and taunted the parents of the slain children. In photos on the website, someone is holding up their middle finger in front of the signs.

Pazienza assisted police with their investigation after Truelove told him he was behind the thefts.

j.wojtas@theday.com