Ground beetle

I had a gardening day, catching up with lots of jobs, planting up hanging baskets and pots and weeding the herbaceous beds. I found lots of interesting insects - caterpillars, shield bugs, nice beetles (ladybirds) and nasty beetles (lily beetles)...and this lovely ground beetle. I think it might be a Pterostichus species, but right now I'm wishing I'd concentrated more when I attended Brian Eversham's course on ground beetles! Beautiful creature anyway!