ID help

Can anyone identify this small fly for me please? Found in Norwich a couple of days ago. It's about 5mm long. I tried ObsIdentify but it kept saying it was Tachypeza nubila which I’m not sure is right. I'm sorry the photos are so bad - it was very mobile despite being kept in the fridge overnight. More information in the alt text and I can try and post higher resolution photos if necessary. Many thanks.