Lee Peacock, 49, was charged by the Metropolitan Police with the murders of Sharon Pickles and Clinton Ashmore in Westminster earlier this month.
Peacock, of Harrow Road, west London, appeared at Westminster Magistrates’ Court on Monday morning after being arrested last week.
Although he was taken to the court in police custody, he appeared at the two-minute hearing by videolink from elsewhere in the building.
Peacock, who gave no indication of plea, spoke only to confirm his name, date of birth, and address.
He was remanded in custody and will appear next at the Old Bailey on Wednesday.
The charges came after officers went to a property in Ashbridge Street at 9:30 p.m. on Aug. 19, when concerns were raised for the welfare of those inside.
Police found Pickles, 45, who was pronounced dead at the scene.
A few hours later, at 2:15 a.m. on Aug. 20, officers were called by London Ambulance Service to a second property in Jerome Crescent, around half a mile away, where they found Ashmore, 59, who was also pronounced dead at the scene.
By Ted Hennessey