A loaded handgun was found on the ground near the entrance to Milton High School Friday morning, leading to a shelter-in-place order, officials said.
Deputy Police Chief Mark Alba said a man walking along Canton Avenue near the intersection with Gile Road spotted the gun around 9 a.m.
The intersection is one of two entrances to the school. The shelter-in-place order began around 9:12 a.m. and was lifted just before 10:27 a.m., officials said.
The person who found the gun brought it to the police department, and officers returned to the intersection to search for more evidence, using gun-sniffing dogs, Alba said.
No additional evidence was found, and Alba said the investigators are trying to determine how the gun ended up on Canton Avenue.
John R. Ellement can be reached at john.ellement@globe.com. Follow him @JREbosglobe.