Big creature on the front lawn

All I have are fragments. Saw it a few years ago. Seems it mostly takes place in this two story old style home. Some sort of box or container that has something evil inside. I remember someone with a rifle and some shootings inside the house. Whatever was in the container escapes and its now on the loose. In the final scene this creature is now outside on the front lawn at least 30 feet tall surrounded by police all pointing up and shooting at it. That's about as much as I can put together. Please help me out of this misery trying to remember what this movie is. Thank you for your help.