Say there was a heavily armed gang of criminals holed up in a building somewhere in Victorian London. Sending a few guys with pistols, in such a situation, is deemed to be not nearly enough firepower. What would the London police have done instead? Would their solution just be "more men!"? Would they be armed with, say, rifles instead of pistols? Would they set up Maxim guns in a perimeter around the building? What was the police response to overwhelmingly well armed criminal gangs?
The police would ask for military help. It's not exactly Victorian era but in 1910 two Latvian anarchists,(what we would these days call terrorists) after shooting three unarmed police after a robbery were indeed holed up in a building and besieged by police. They were armed with superior automatic pistols and thus the police asked for military help and the home secretary sent soldiers in to assist with plans to include even artillery pieces. However, the besieged building caught fire and was allowed to burn.
In the Victorian era proper and immediately before and after it, for example during the wide-spread popular unrest following the publication of the People's Charter of 1838, there were several riots where military forces were sent in to assist.