Medical examiners have been unable to determine the cause of death of a pregnant woman found in the house of a private security guard who killed himself on the roof of a downtown Washington office building this week, according to authorities.

Police said the mystery of the two deaths, which took place a day apart, deepened Thursday despite an intensive investigation in which detectives spent more than 30 hours at the guard’s home, in the gated community of Fairlawn Estates in Southeast.

It could take weeks for test results to determine the cause of death for 31-year-old Kisha Lashawn McCall, who was found Wednesday, and whether it is linked to the apparent suicide of Travis Bostick, 23, who was found dead of a gunshot wound Tuesday.

Relatives could not be reached to comment or declined to speak. “It’s a tragedy, and we have no comment,” said a woman who answered the phone at one of the McCalls’ residences.

Few details could be learned about McCall and Bostick, although a neighbor, who was frightened by the situation and declined to be identified, said the woman had moved into the house, in the 2200 block of Retta Gilliam Court.

Court records in Maryland show that Bostick was in the process of divorcing his wife in Prince George’s County and that the proceedings were contested. A hearing for the final divorce decree was scheduled for September.

Bostick had worked for about two years for C&D Security, which is headquartered in Colorado, according to Troy Thames, the company’s vice president. The company provides contracted armed guards to the Federal Protective Service, which polices government offices.

Bostick’s body was found on the roof of the General Services Administration building, in the 1800 block of F Street NW. D.C. police and a GSA spokesman said he committed suicide. D.C. police also confirmed Bostick’s identity.

McCall’s body was found in Bostick’s home. Two D.C. law enforcement sources confirmed an account that one of McCall’s relatives gave to WJLA (Channel 7). The man told the station that a 13-year-old relative found McCall’s body in the garage.

D.C. police officers kept the gated neighborhood sealed off for more than 30 hours, with detectives and other investigators at the scene throughout the night. Authorities would not describe what they learned or what evidence they seized. They said that McCall’s body showed no signs of trauma.

Trishula Patel contributed to this report.