Hall

When you walk into the room, a young couple look up from a game of cards.
The man puts his cards down on the table and shake your hand.
"You must be the detective. John popped in to let us know you would be by. I am Mr. Smith and that is my wife Mrs. Smith. I hope you having luck with your investigation. I am afraid we will not be of much help. After the picnic this afternoon, my wife and I came here for a game of cards while waiting for dinner. After some time, Mrs. Mar walked by the doorway to the kitchen and the next thing we hear is a scream."
You glance at the door and ask if it was open all the time.
Mrs. Smith looks up from studying her cards.
"The door was open all the time. First we saw Mrs. Redly walk to the greenhouse, then a little later, Mr. Mar walked to the greenhouse also. A while later Mrs. Mar walks past and the rest you know."
"So, no one entered the kitchen besides Mrs. Mar?"
"Oh dear, we can't be sure of that." Mr. Smith looks concerned, "You see there is a back door on the house and we couldn't see the kitchen door from here. All we can really see is the front hall, and the parlor, sitting room, and greenhouse doors. They were closed the entire time except for when Mr. Mar and Mrs. Redly left the house."
You realize there is nothing more for you to learn here.