Police have warned members of the public not to be out on the streets alone.
Police have linked two murders of University Nahid Almanea was stabbed 16 times as she walked down a path in a busy Colchester street on Tuesday morning at 10.30am.
Police are also investigating the murder of James Attfield was stabbed 100 times who was murdered in similar circumstances.
A third woman was attacked but managed to escape as she jogged along Peache Road june 19th at 10pm.
She put up a fight and made her way home and immediately contacted Police.
Essex Police have eliminated a 19 year old from their investigation continuing to hunt the killer.