Security guards at a Food and Drug Administration laboratory in Bothell called police to say they had fired gunshots just a few minutes after contacting a suspicious person in a car in the parking lot Friday morning, police said.

A 15-year-old boy sped off after the gunfire at about 7 a.m., leaving muddy ruts through a parking strip. He was involved in a hit-and-run accident about a mile away on state Route 527 and then was tracked to his home, said Bothell police Sgt. Cedric Collins.

The boy was hurt, but it was unclear if the injury was from the shooting or the crash, Collins said. Initial information indicated he had been shot. Fire department medics took him to Evergreen Hospital in Kirkland where he was treated and released.

Collins said the boy was held for detectives with the Snohomish County Multi-Agency Response Team, which took over the investigation.

It's not clear why the teen was suspicious or what prompted the security guards to fire.

The two guards were under contract to the Federal Protective Service, a division of the Department of Homeland Security that provides security at federal buildings.

"The FPS is working with local law enforcement to investigate this incident," the agency said in a statement attributed to spokeswoman Jacqueline Yost.

The FDA laboratory, called the Pacific Regional Lab Northwest, analyzes samples of products for safety and compliance with regulations. It is located in a suburban business park

The teen is a student at the Secondary Academy for Success, an alternative high school adjacent to the FDA building, said Northshore School District spokeswoman Leanna Albrecht. The school was in a modified lockdown while some students were questioned by police.

The school and the FDA building are separated by a fence, and there's no history of problems between students and the FDA, Albrecht said.

Officials weren't saying how a 15-year-old came to be driving or what brought him to the attention of the security guards.

"Everything went downhill from there," Collins said.