OLATHE, Kan. -- Prosecutors said Kelsey Smith, the Kansas teen who was abducted and killed over the weekend, was strangled.

Smith's body was found Wednesday. She disappeared June 2 after buying a gift at Target for her boyfriend.

Surveillance video showed someone running up behind Smith in the parking lot after she had put her shopping bag in her car.

Johnson County District Attorney's Office spokesman Brian Burgess said Friday that some type of ligature was used to strangle Smith after she was abducted.

He did not specify exactly what was used to kill the 18-year-old Smith, or give details of how or where it happened.

Prosecutors may seek the death penalty for Edwin R. Hall, the 26-year-old Olathe man charged with first-degree murder and aggravated kidnapping in Smith's death. His bond is set at $5 million.

District attorney Phill Kline did not rule out moving the case to federal court. Kline said that he does not necessarily believe Smith was killed in Kansas but the fact that she was abducted in Johnson County gives his office jurisdiction.

Smith's body was found in Missouri.

Using the last pinpointed signal from Smith's cell phone, searchers found her body in a wooded area near Longview Lake on Wednesday afternoon. Police said a tip from the public led to the arrest of Hall. Police said Hall was questioned on Wednesday afternoon and was arrested a few hours later. Hall's next appearance was scheduled for June 14.

Meanwhile, more than 500 people turned out at a memorial gathering Thursday night to honor Smith.

It was held at Shawnee Mission West High School, where the girl graduated a few weeks ago. Winds were too strong for the candlelight vigil that was planned.