where is the latter place located?
Wisconsin, United States.
Waukesha, Wisconsin
Waukesha () is a city in and the county seat of Waukesha County, Wisconsin, United States. It is part of the Milwaukee metropolitan area. 
when did slender man the movie come out August 10, 2018 was the movie based on any incident? No - Slender Man  is a fictional supernatural character could you please describe him? Thin, tall humanoid with a featureless head and face, wearing a black suit. by whom was it developed? Eric Knudsen is it related to any stabbing incident? Slender man is not related to any stabbing incident. However, Slender Man readers were connected to several violent acts, particularly stabbing of a 12-year-old girl in Waukesha, Wisconsin.
wiki:11744531
Waukesha, Wisconsin [SEP] Introduction
Waukesha () is a city in and the county seat of Waukesha County, Wisconsin, United States. It is part of the Milwaukee metropolitan area. Its population was 70,718 at the 2010 census. The city is adjacent to the Village of Waukesha. I-94, U.S. 18, WIS-59, WIS-164, and WIS-318 creates a beltway bypass around Downtown Waukesha.