Underlying theories that help explain spatial behavior of criminals include environmental criminology, which was devised in the 1980s by Patricia and Paul Brantingham,[2] routine activity theory, developed by Lawrence Cohen and Marcus Felson and originally published in 1979,[3] and rational choice theory, developed by Ronald V. Clarke and Derek Cornish, originally published in 1986.[4] In recent years, crime mapping and analysis has incorporated spatial data analysis techniques that add statistical rigor and address inherent limitations of spatial data, including spatial autocorrelation and spatial heterogeneity. Spatial data analysis helps one analyze crime data and better understand why and not just where crime is occurring.