Sorry this is so long. I'm having a dilemma over whether my actions were called for or if I overreacted.

Yesterday afternoon I was resting on the couch while LO was taking his nap. He had woken up (too early) so I was awake and just deciding when to get up to get him. I heard a noise outside on the front step so I glanced up out the window, expecting it to be FedEx delivering LO's new carseat. I was surprised to see our neighbor from across the street on the steps. I got up and went to the door to see what was going on and she was in her driveway with the box that I was expecting to be delivered! It was a Britax carseat box which I could clearly see from the door. She looked over and saw me in the doorway. We made eye contact and then she looked away. I was going to go outside to ask her about it but at this point DS was screaming his head off so I went to go grab him from his crib. 30 seconds later the neighbor and our box were nowhere to be seen. I checked the online tracking and sure enough it said the box had been delivered to the front steps. So, I called the cops. I know most people would go to the neighbor's house to see what was going on, but these people are CRAZY. The cops are there at least monthly, sometimes arresting someone and one time DH saw one of them beating up a female police officer. The officer that responded to my call went over and got the carseat for us. The neighbor told him that she had no idea who it belonged to and it was practically in the street so she put it in her backyard for "safekeeping". We've personally never had a problem with these neighbors before so I do feel like maybe I should've given her the benefit of the doubt and not called the cops but I saw her on my steps and the box has my name and address on it!

Did I overreact? Should I apologize to her? Or was she really stealing our carseat?