The murder case

The murder case in Mary Barton reminds me of that in To Kill a Mockingbird, in that it seems to have been processed in a surprisingly slipshod mannner, but it is too long ago to know whether it was realistic or not. In the previous book I read, Bleak House, a contested will had been disputed in court for decades. That case had been modelled on two real cases that had lasted for years and had cost fortunes. In Mary Barton, a murder occurs Thursday one week and is tried on a Tuesday about twelve days later. That seems incredibly quick. There are other aspects about the case that seem odd from this day and age:

• Mary's aunt Esther searches the scene of the crime and discovers a piece of paper that had been used as wadding. That wadding actually contained some incriminating evidence, so Mary wisely destroys it. However, it seems very odd that the police did not find it. Perhaps police were not very professional in those days.
• The police did, however, find the murder weapon. A policeman dressed up as a workman and entered the suspect's mother's home. He asked her whether the gun was her son's. Was he allowed to do this? Shouldn't he have applied for a warrant? Wouldn't he have had to identify himself as a policeman. If not, would this evidence be admissible?
• The murder suspect was walking with another man to Liverpool. This man could have provided him with an alibi. That being so, why did Mary have to hunt him down rather than the police?
  
• The man who could have provided the alibi was a sailor, and he had nearly sailed out of Liverpool by the time Mary found him. Supposing he had sailed, what would the court have done? Would they really have hanged the man?
  
• Not only is it a very short time from crime to trial, it seems that the case has to be completed in a very short time. Couldn't the suspect's lawyer ask for an adjournment, especially in the event of the suspect's alibi having sailed off?
  
• Mary overhears some lawyers speaking about the case on the train. They said that usually a jury would not convict on circumstantial evidence, and that usually the police would have spent more time collecting evidence; however in this case the circumstantial evidence was very strong. In addition, the victim's father was rich and powerful and bringing a lot of pressure to bear on a conviction being obtained quickly. Was the judiciary system really that spineless?