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Family and police have been searching for 17-year-old Brissa Romero after her family said she vanished exactly week ago while on her way to a holiday party at a bowling alley, but never made it.
Vernon Hills police said cell phone data analysis led investigators to the retention pond at that intersection Monday morning. When they arrived, a resident who had been walking around the pond and pointed out a backpack that had floated to the edge of the water. Police said the backpack appears to belong to Romero.
Vernon Hills police then reached out to the Countryside Fire Protection District who brought in special teams to search the pond. In the water, they found Romero's Nissan Rogue.
WATCH: Full update from Vernon Hills police
Police update on search for Brissa Romero
Police said that based on the condition of the car and all the evidence they have, it appears Romero was in the car when it drove into the pond. Police did not find her body in the car or during their search Monday.
Police said they found video footage from a fast food restaurant one to one and a half miles away from the pond that shows Romero parking, walking into the restaurant, walking out and then driving out of the parking lot. She is by herself in the footage, police said.
The video was taken about 15 minutes before her last cell phone ping registered in the area of the retention pond, police said. Police said the car traveled as far as 60 feet into the pond, and they believe she may have been unfamiliar with the area - which is a T-shaped intersection where the driver must turn right or left to remain on the road - and thus driven through the intersection, down an embankment and into the pond.
Evidence technicians are now analyzing that vehicle.
"Based on the condition of the vehicle and all the evidence we have at this point, it appears that Brissa was in that vehicle when it drove into the lake," said Vernon Hills Police Chief Patrick Kreis.
Meanwhile, the search has now turned into a recovery operation, police said.
"It's our belief that we need to continue to search this pond, and that is really the sole efforts of our search at this point," Kreis said.
Brissa's sister, Dulce Romero, said there is still hope for their family that their little sister, the youngest of five siblings, will be home for the holidays.
"The vehicle has no body inside. They will be searching the pond and to see if Brissa's body is in there. Until now, in my heart, I still believe she's out there," Dulce said.
Brissa's sister said police will be resuming their search efforts at the retention pond on Tuesday morning at 8 a.m.
This comes after new surveillance video, shared by her family on Sunday, shows the Carpentersville teenager returning to her job in Schaumburg to pick up her iPad.
Surveillance camera captures last known video of missing teen
Her family said it's the last known documented video of her before she left for the party.
Brissa's family is offering a $14,000 reward for any information that could help them find her.
Brissa is 5 feet tall and weighs 115 pounds. Authorities asked anyone with information to contact Sgt. Webb with the Carpentersville Police Department at 847-551-3481 or QuadCom Dispatch at 847-428-8784.