Possible Clues:

• 'A show-off' -- what locals never said about 1880s Whitechapel detective?
• I get proper treatment for being so selfish
• One self-boosting drug obtained, something really good
• Elizabeth understood serial killer being only out for himself
• European caught notorious criminal -- one with high self-opinion
• I promote myself — I get proper plays
• Self-absorbed type given drug became murderer
• Drug brought 'rush' for each self-indulgent person
• Female finally took Jack for attention-seeker
• 'e captured a murderer and 'e suits 'imself