Police spokesman Capt. Paul Kifer said that the medical examiner is awaiting the results of toxicology tests on Allison Keyonda Pluck of Hagerstown to rule on a cause of death.
Pluck and the children, 18-month-old Shania Unique Gill and 6-month-old Shameka Allison Gill, were discovered Monday in their closed car at Western Heights Middle School. The temperature reached 90 degrees that day, although authorities haven't said if that was a factor.
Police had trouble finding relatives for Pluck, who is from Guyana in South America, so they couldn't release her name any sooner, Kifer said. Washington County Department of Social Services workers had consulted with the Guyana Embassy and helped put police in touch with Pluck's sister in that country.
Pluck has been in the U.S. since 2006 or 2007, police said, and had lived in Hagerstown since 2012. She had worked at Wal-Mart in Frederick, but Kifer said she quit that job a few months ago.
Investigators have determined through surveillance videos that Pluck bought a DVD player at a Hagerstown Wal-Mart about 6 a.m. Monday, then arrived at the school at 6:15 a.m. Kifer said Pluck's car pulled out of a visitor's parking lot, then drove over a grassy area behind the school, which was out of sight of surveillance cameras.
The bodies were found about 4:40 p.m.
Kifer said police have no idea why Pluck was at the school.
Pluck's body will be returned to Guyana for burial, Kifer said. The children's father, who was not married to Pluck, will arrange for their burial in the U.S.