“We pressed the buzzer of Roberta Fenn’s apartment. Somebody answered the signal and buzzed the door open. We got up to where we could look in the apartment. We could see Nostrander’s body. I dragged Bertha away because I thought the murderer must have been in the apartment.”
Pellingham nodded.
“He wasn’t,” I said.
“How do you know he wasn’t?”
“Because we watched the building. He didn’t leave. No one left the building, except a somewhat elderly woman. Then the police came.”
Pellingham said, “That’s the strange thing about it. After the police got that anonymous tip over the telephone, two detectives went down there. They rang Fenn’s apartment, and somebody buzzed the door open. They went up, and there was no one in the apartment.”
I said, “The night I went up to call on Roberta Fenn, Nostrander knocked at the door. He hadn’t buzzed the outer door. Roberta stalled him along, and then told me I’d better leave. I left right after Nostrander did. When I got out of the street door, I looked up and down the street. I didn’t see Nostrander anywhere.”
“Well, what’s the answer?” Pellingham asked impatiently.
I said, “Nostrander must have had some other friend in the apartment house, a friend on whom he’d been calling pretty regularly. It’s pretty reasonable to suppose that this would be a girl friend, and that when she realized that Nostrander was still infatuated with Roberta Fenn she’d be pretty jealous. Marilyn Winton has the apartment right across the hall from Roberta’s apartment.”
“After the murder, various people came to that apartment house, rang the bell of Roberta Fenn’s apartment, and the entrance door was promptly buzzed open. If Roberta Fenn had returned to her apartment, she’d have been killed, but whenever the wrong people entered the apartment, they didn’t find anybody there. What every one has overlooked is that the occupant of any apartment can press the buzzer which opens the street door. Figure it out for yourself.”