A 19-year-old man from Colchester has been arrested on suspicion of murdering Saudi Arabian student Nahid Almanea.
Essex Police said the teenager was initially arrested overnight on Thursday following reports by a woman that a man attempted to grab her as she jogged through the town.
He was then arrested shortly after 4pm on Friday in connection with the investigation into the murder of Nahid Almanea, 31, who was knifed to death on Tuesday.
Almanea was stabbed 16 times as she walked to Essex University on June 17.
Essex Police said in a statement: "We have arrested a 19-year-old man from Colchester in connection with the investigation into the murder of Nahid Almanea. The man was initially arrested shortly after midnight today for a separate offence of assault.
"His arrest followed a report from a woman that while she was jogging near Peache Road, Colchester at around 10pm, on Thursday June 19, a man had approached her and tried to grab her. She was able to fight him off and made her way home and then immediately contacted police.
"Police searched the area and a man was subsequently arrested and taken into police custody. Following further enquiries he was then further arrested shortly after 4pm today in connection with the murder investigation."