A St. Mary’s County man is facing arson and related charges after Deputy State Fire Marshals determined a fire set on the rear deck of a Waldorf home earlier this month was intentionally started amid what investigators describe as an ongoing domestic-related dispute.
An occupant of the home in the 4900 block of Morraine Street discovered the fire on the rear deck shortly before midnight on Friday, Sept. 11, and put it out with a garden hose. The fire wasn’t reported to authorities until the following morning, when the Office of the State Fire Marshal was called in to investigate. Investigators determined the fire originated on the deck and had been intentionally set. Seven people were inside the home at the time; no injuries were reported, and damage was estimated at $1,500.
During the investigation, Deputy State Fire Marshals, assisted by the Charles County Sheriff’s Office, identified Demartez Trequan Thomas, 29, of California in St. Mary’s County, as the person allegedly responsible. Investigators determined Thomas was at the residence around the time the fire was set and learned he had an ongoing domestic-related dispute with one of the occupants.
Deputy State Fire Marshals assigned to the Southern Regional Office, with assistance from Maryland State Police troopers from the Leonardtown Barrack, took Thomas into custody without incident at his St. Mary’s County home Tuesday evening. He was transported to the Charles County Detention Center and charged with first-degree arson, first-degree malicious burning, malicious destruction of property, and eight counts of reckless endangerment. He is being held without bond. The charges against Thomas are allegations, and he is presumed innocent unless and until proven guilty in court.
The case is the latest in a string of Waldorf-area arson cases tied to domestic disputes that Deputy State Fire Marshals have investigated in recent years, including an August 2025 case in which a Waldorf man was charged with attempted murder and arson after allegedly setting his own home on fire following a domestic dispute, and an arson charge filed against a Port Tobacco woman after a house fire in July. Under Maryland law, first-degree arson — which applies to fires endangering human life or causing more than $50,000 in property damage — carries penalties of up to 30 years in prison and fines up to $50,000, while second-degree arson carries up to 20 years.
