"I will," the 14-year-old would say, followed by a pause. "In a minute."
The girl's family is now asking people to take the minute she often wanted -- and use it to see if they recognize the image and voice of a man police say is a suspect in last month's killings of Libby and her friend Abigail "Abby" Williams.
Libby and Abby, 13, were found slain near an Indiana hiking trail on February 14. Police say Libby had taken cell phone video of a man shortly before the girls were killed, and that the man is suspected of killing them.
"Give her the one minute she always asked for, to really study the picture and listen to the audio clip," Libby's grandfather, Mike Patty, said at a news conference Thursday.
'Someone out there knows this person'
Libby and Abby, friends and fellow softball players, were dropped off February 13 near an abandoned rail bridge over a creek so that they could hang out and walk around, police said. They were near their hometown, Delphi, a city of about 2,800 people roughly 65 miles northwest of Indianapolis.
They were reported missing after they didn't arrive at a designated pickup time. Their bodies were found the next day
near a trail about a half-mile upstream from the bridge, police said.
Authorities last month released a grainy photo of a suspect: Someone who appears to be a white man wearing blue jeans, a blue coat and a hoodie, according to police. They still are trying to identify him.
Police said that the photo came from a video that Libby had taken on her cell phone.
They also released audio of a man's voice
that the phone video had captured. The words "down the hill" are heard.
The image and audio have circulated publicly for more than two weeks. Patty on Thursday urged the public to take a close look.
"Someone out there knows this person or persons. He's someone's neighbor, co-worker, family member, friend, husband or acquaintance," he said.
Police have said they have more video but they are not releasing it.
Authorities urge anyone with information about the killings to call their tip line
. They say there's a reward of more than $220,000 -- boosted in part by donations from Indianapolis Colts owner Jim Irsay and former Colts punter Pat McAfee -- for information leading to the conviction of those responsible for the girls' deaths.
More than 11,000 tips have been received, but more information is needed, Indiana State Police Sgt. John Perrine said.
There is no indication that the case is tied to other homicides, Perrine said.