Chain of custody

Chain of custody, by definition, is a list of all people that came in contact/posession of an item of evidence. Chain of custody is like a ladder. The bottom tier of the ladder is the crime scene/ collection site. The top tier of the ladder is the trial/courtroom. All the rungs from the bottom to the top are the people who collected it until the second to top tier when it gets into the lawyers hands for the last tier.  A chain of custody is needed because is any link was kinked, they would know who kinked it, and because if there is no chain, there is a strong possibility it would become contaminated an then would prove futile. i believe it is a good idea to have a standard practice concerning evidence collection. I would not want to lose my job for someone else's mistake. Also, if there is no proper chain of custody, you would have no idea where the original evidence is. Say if you were the investigator and you needed to take another look at the bloody smith and wesson revolver and bullet to see if you missed something that might be a vital aspect of the case. But when you get to the locker to check it out, the person says its not here someone checked it out but there is no details of who checked it out, when it was really in the firearms/ballistics lab, your first thought might be it's ins someone's hands here or it could possibly be loose on the streets again which would make that gun even hotter and possibly with a higher body count attatched to it....you would just never know. And it is of vital importance to a trial, if you cant say who has had the evidence the whole time, who is to say you really ever had what you said you had?