OVERLAND PARK, Kan. -- A leader of the church attended by Kelsey Smith's family said police have told him that they believe a body found today is that of the missing 18-year-old.

Hillcrest Covenant Church director Don Mapes said two pastors from the Prairie Village, Kan., church went to the Smith home after hearing from police.

Authorities searching for Smith confirmed that a body was found, but have not confirmed whose body it is. Grandview, Mo., police did confirm that the body was found on the northwest edge of an area where searchers were looking for Smith, KMBC-TV in Kansas City, Mo., reported.

Police planned to update developments at 4 p.m. CDT news conference.

The search activity has come to a virtual standstill and crime scene tape has been hung, KMBC reported.

It is an area north of the area where more than 200 federal agents, police officers and police academy students focused their search efforts for the 18-year-old girl.

The area investigators are searching is east of U.S. 71 Highway and north of Missouri Highway 150.

Earlier, authorities said the search moved to an area around a park south of Kansas City, Mo., based on information from cell phone technology.

Police said Smith's phone passed through several sites along a route that led to an area around the park. Experts have been analyzing signals from the girl's cell phone on Saturday night after she was abducted outside an Overland Park Target store.

Police on Tuesday night released enhanced surveillance video of a pickup truck that may be connected to Smith's weekend disappearance.

Officers said they need help finding a dark-colored, mid-1970s Chevrolet pickup truck. The pickup was seen in the Target parking lot at the same time Smith was at the store at 95th Street and Quivira Road Overland Park, Kan.

The Chevrolet pickup was also seen at Macy's parking lot, where Smith's car was later found, police said. There was no visible license plate on the pickup, police said.

Smith, who graduated from high school less than two weeks ago, left a Target store around 7:10 p.m. Saturday and put packages into her car when someone ran toward her, police said.

Earlier on Tuesday, police released video of the parking lot encounter.

"You see two individuals come together, and there is no separation of those two individuals," Overland Park Police Chief John Douglas said. "So it is easy to conclude there was some kind of incident at the back of the car. Then the car leaves."

The tape was "just not detailed enough" and was being enhanced at a forensics lab, Douglas said.

"We see activity," Douglas said of the videotape. "We are moving on the assumption -- because the prudent thing to do is to treat this as an abduction -- that there was some kind of force involved."

Anyone with information in the case can call the TIPS Hot Line at 816-474-TIPS. Callers can remain anonymous.

Police said they were pursuing more than 500 leads in the disappearance of Smith, which is an "extraordinarily high number for a case like this," Douglas said.

Person Of Interest Still Sought

Meanwhile, investigators have not identified a man they considered a person of interest in the case. Police earlier released video of Smith walking into and out of Target and of the man who was seen close to the victim, said Detective Bob Miller.

"He walked in shortly after her and left shortly before her, and is obviously parked out somewhere by her," Miller said.

Police were not calling him a suspect, but said he may have information, and they wanted to speak to him.

Reward Increased

About two hours after Smith disappeared, her grandparents found her gray 1987 Buick in a parking lot at a nearby mall in Overland Park with her purse and packages still inside.

Meanwhile, Miller said the Smith family was bearing up "as well as can be expected." They have increased the reward for information about Kelsey's disappearance to $30,000.

Smith's father, Greg Smith, has been in law enforcement for 16 years. He earlier described his daughter as an outgoing young woman who plans to be a veterinarian.

Investigators said they don't know if Smith was picked at random or abducted by someone she knew. But Kelsey Smith's 23-year-old sister, Stevie Hockersmith, said she was sure her sister did not know the man police were seeking for questioning.