WASHINGTON (DC News Now) -- D.C. police said Monday that authorities charged a man with murder after three people died after a house fire in Southeast broke out Sunday morning. A D.C. judge ordered 56-year-old Robert Simpson to be held without bond Monday afternoon, calling the circumstances of the case "horrific." According to the Metropolitan Police Department (MPD), on Saturday, Oct. 5, officers responded to the 3400 block of 23rd St. for reported destruction of property. Once on the scene, police found out that someone had broken a window at the home and left before officers arrived. About two hours later, DC Fire and EMS (DCFD) responded to the same location for a report of a fire in the back of the house. When crews arrived, they saw an extinguished fire in a trash can. Man charged in connection to death of 5-year-old boy in DC, police say Firefighters notified fire investigators who determined that the fire had been intentionally set by Simpson, according to MPD. Several hours later, at about 3:40 a.m., officers responded to the same home for a domestic assault. When they arrived, there was no suspect on the scene. The victim told officers that Simpson had assaulted her earlier that day; however, she showed no signs of injury and did not require any medical care, according to police. Officers stayed in the area for over an hour trying to find Simpson but were unsuccessful. Then, just before 5:30 a.m., MPD and DCFD responded to the same location again for the report of a structure fire. After firefighters extinguished the flames, responders found three people inside the home. MPD said Monday that 64-year-old Ronald McKinnon and 34-year-old Jessica Cunningham died at the scene. The third person who was inside the home, 85-year-old Margaret McKinnon, died at the hospital Monday morning. New court documents in the case detail what they believe were Cunningham's pleas for help over the phone when the fire broke out, screaming and struggling to breathe, saying "He came back," and "The house is on fire." "What makes this even more tragic, people were doing the right thing. People responded, they worked very hard. Still, the outcome is terrible," DCFD chief, John Donnelly, said. 10 people rescued from Potomac River in Montgomery County After the deadly fire, officers found and arrested Simpson in the 1500 block of Mississippi Ave. in Southeast. MPD Chief Pamela Smith explained the decision not to stay at the home after multiple calls came in. "We put our folks back in service until we can find some other identifying information or circumstances that require us, to place someone at the home. We just wouldn't just sit officers at a particular location for an extended period of time," Smith said. Authorities initially charged Simpson with the arson that occurred at around 9 p.m. the night before the deadly fire. As the investigation continued, authorities charged Simpson with murder in connection to the deaths. According to MPD, investigators believe that Simpson and Cunningham had a romantic relationship previously and that, at one point, Simpson lived in the home with the victims. MPD said it is working alongside DCFD, the U.S. Attorney's Office and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to determine if more charges will be filed against Simpson.