Essex Police have advised people in Colchester not to visit isolated places alone, after two fatal knife attacks in the town in three months.
Nahid Almanea, 31, was found on Saturday near the University of Essex campus. She had been stabbed 16 times.
James Attfield, 33, was stabbed 100 times in Castle Park in March.
Police say a man in his fifties is helping them with their inquiries.
More top news
Northern and Western areas keep best of sunshine in next few days.
Eduardo Paes says that despite Brazil's political turmoil Rio de Janeiro is ready to welcome the world for the 2016 Games.
France will host the tournament from June 10 to July 10, with hundreds of thousands of fans set to flock to the country.