On a Sunday morning-Riddle

There was no power on a Sunday morning. Everyone notices Mehul's death all of a sudden. When the police operated their investigation, he discovered that four people were present in the house at the time of the murder. According to the four suspects- a. Sanjana took her dog, bravo for a walk b. Alia was busy keeping dishes in the dishwasher c. Gogo was during his assignment d. Kushal was having his lunch. However, the murderer was arrested by the police. How did the police figure out who was the murderer?