Jane Bennett, from Birmingham, talks about coming to terms with the death of her son, after he was killed by a drink diver.
She is backing the West Midlands Police Christmas campaign.
More top news
A large tent has been put up around the area while investigations continue.
The kind gesture touched the hearts of many who shared and retweeted words of support for the officer on Twitter.
Two workers were forced into a back office as the robbers tried to force their way into a safe, police say.