WINDERMERE, Fla. -- A "black box" inside a minivan helped state troopers solve a crash from more than a year ago.
WFTV Eyewitness News reported in July 2012 when Carla Matheson was killed along Overstreet Road in Windermere.
Her husband, Mark Matheson, was also injured.
The recorder determined the driver was going 30 mph over the posted speed limit.
Time has taken its toll on flowers, a cross and a tiny American flag left for Carla Matheson.
Time has also allowed the Florida Highway Patrol to build its case and arrest teenager Cody Robinson-Banks for vehicular homicide.
"It takes time to gather all the information. We're writing the last chapter of someone's life, so we want to make sure we get it correct," Sgt. Kim Montes with Florida Highway Patrol said.
Troopers had high-tech help. They used the black box recorder in the minivan driven by Robinson-Banks to determine he was going 60 mph in a 30-mph zone when his van hit the car driven by Mark Matheson.
"It's commonly used to kind of support what investigators are already proving through physical determination with physical evidence. So it's a way to back up the data that we already have," Montes said.
The recorders are found under the hood in the engine compartment and save information on speed, seatbelts and airbag deployment.
Federal law will require all American-made cars to have black boxes by 2014.
Robinson-Banks was also charged with reckless driving causing serious bodily injury because Matheson's husband was hurt in the wreck.
No one from the victim's family wanted to comment for the story.
Carla Matheson's obituary from last year said she enjoyed helping people around the world in places like Rwanda and South Africa.
Video: WFTV Orlando