The Bertillon System:

This was a system that recorded the physical measurements of criminals through photography and records. This would help police to identify criminals who committed repeated offences. Physical measurements were made that would only apply to a single person. The inability of the force to catch the Ripper led to the adoption of the Bertillon System in 1894.

Measurements of suspects were made, mug shots captured and records stored away in a central place. Physical measurements were eventually replaced by the fingerprint system a few years later, but Bertillon's photographic methods continued and are used still today.

Improvements in Communication:

Police only could communicate over distances by a whistle in 1888. By the turn of the century, the police were using telephone lines to communicate with one another. The H Division received their first telephone line in 1901 and their station had one installed in 1907. Them, in 1909, the H Division received bicycles which aided in the catching of criminals.

Improvements in environment:

The authorities in London began to improve health and housing in the district, with surrounding boroughs receiving street lighting to aid in the sight of activities in the streets at night. The murders were important in the creation of two laws:

The Houses of the Working Classes Act (1890) - the new London County Council had the opportunity to redevelop housing and replace slums with mass low-cost housing
The Public Health Amendment Act (1890) - local councils were given greater powers to improve toilets, paving, and many sanitary services

Despite these reforms and no more serial killings, murder continued throughout the 1890s. Many youths pretended to be Jack the Ripper to frighten women. Further, violence increased against prostitutes.

The diagram below comes from: Alphonse Bertillon's, Identification anthropométrique (1893)