A chilling 911 tape was released over the weekend from the Nov. 25 fatal shooting along I-270 in Ohio, which has been linked to at least one of the other 11 shootings in a five-mile area.

And on Sunday, authorities announced they'd set up a post office box as a way for the shooter or shooters to contact them.

Two days before Thanksgiving, Gail Knisley (search), 62, was struck by a bullet that pierced the driver's side door of the car she was riding in. It narrowly missed her best friend, Mary Cox, who was behind the wheel. The two were on their way to go shopping and have lunch.

A distraught Cox called 911 (search) while she was still driving to report the horrific scene.

"I'm in the car and my girlfriend is ... been shot," Cox says on the tape. "I don't know where the gun came through, so I don't know where — I don't see anything. I'm driving."

When asked if Knisley was still in the car with her, a sobbing Cox replies, "Yes, she is and she's groaning and, and she's terrible."

Thus far, Knisley has been the only victim in the shootings — and the only person to have been hit by a bullet. A funeral and burial for Knisley, a mother and grandmother, was held Saturday in her hometown of Washington Court House (search), about 40 miles southwest of Columbus (search ).

In a press conference Sunday, police urged the person or people responsible to call or write them at the newly established hotline or post office box.

"Please contact the sheriff's office so we can establish a dialogue," said Chief Deputy Steve Martin (search) of the Franklin County sheriff's office.

Anyone with tips about the shootings can also call the phone number established, (614) 462-4646. Other information is available on the sheriff's office Web site.

Though police have stopped short of calling the suspect a sniper, they have said the fatal shooting was connected to at least one other case and was not an accident.

Tests on bullet fragments have definitively linked two of the 11 random shootings that have terrorized a five-mile stretch of I-270 circling Columbus since May, authorities said Saturday. Most of the incidents have taken place in the last seven weeks.

Martin said two fragments were "a definite match," but not enough was recovered from similar shootings to verify further matches.

But investigators said they couldn't rule out the possibility that there were other links among the shootings. Only hours after Knisley was killed, another shooting was added to the list — upping the number to 11.

At a news conference, Martin said one or more people are deliberately targeting drivers. But Martin refused to use the word "sniper" concerning the gunman.

Martin said the term sniper evokes an image of someone with military training lying in wait in the woods while wearing camouflage. The highway shooter could be mobile, he said.

A task force investigating the shootings has received 250 tips, many naming suspects, Martin said. Police have gone out to interview people named in tips, but have not taken anyone into custody for questioning, he said.

The shootings, all on or near a southern section of Interstate 270 (search), took place at different times of day, piercing trucks, cars, vans and pickups, shattering windows and flattening tires.

Martin declined to discuss the type of weapon used, saying it could harm the investigation.

"We have some ideas, but we're not going to discuss those issues," he said.

Extra patrols have been assigned to the section of the highway, which is thick with brush and woods in some parts and bordered by houses, scattered industry and open fields in others.

Ohio's gun deer-hunting season opens Monday, so the public shouldn't be alarmed at the sight of people with shotguns, Martin said. He asked hunters to be alert to anything suspicious.

Fox News' Rebecca Gomez and The Associated Press contributed to this report.