Police: London attacker not tied to terror groups

British counterterrorism investigators do not believe the man who killed four people in last week’s attack in London had connections to al-Qaeda or Islamic State. But they still don’t know whether he told anyone about his plans ahead of time. Khalid Masood plowed a rented SUV into a crowd on Westminster Bridge before stabbing a police officer outside Parliament. Shortly after the attack, an ISIS website claimed Masood as one of the group’s “soldiers.” Two people arrested after the attack remain in custody. Masood sent an encrypted message using WhatsApp shortly before the attack but police have been unable read it. British Home Secretary Amber Rudd said such programs should not be allowed to provide terrorists a meeting and planning platform inaccessible to law enforcement agencies. But privacy advocates say forcing companies to provide ways to access users’ information would violate individual liberty. Masood was not considered a “subject of interest” before last week’s attack.

The Associated Press contributed to this report.