London Stab Attack Victim Identified as American Who Was on Last Day of Trip with Professor Husband

Police said the woman killed in a London stabbing attack was American.

Police have confirmed that the woman killed in a knife attack in London Wednesday was a 64-year-old American woman on the final day of a summer trip.

Darlene Horton was the wife of Florida State University psychology professor Richard Wagner.

She died the day the school's summer study abroad program had ended. The couple was supposed to return to Florida on Thursday, according to the Tallahassee Democrat. 

In a statement Thursday, FSU President John Thrasher said: "There are no words to express our heartache over this terrible tragedy. We are shocked that such senseless violence has touched our own FSU family.

"We will do all we can to assist Professor Wagner and his loved ones, as well as his friends and colleagues in the Psychology department, as they mourn."

The teen allegedly behind the attack was a Norwegian man of Somali origin. He was arrested after the attack, said police.

Read: Trump Supporter Arrested for Attacking Wife, Who Supports Hillary Clinton: Cops

Five others were injured in the attack in Russell Square. They were Australian, Israeli and British, according to police.

The investigation “increasingly points to this tragic incident as having been triggered by mental-health issues,” Metropolitan Police Assistant Commissioner Mark Rowley said.

Two of the people injured are hospitalized, and three others have been discharged, he said.

Rowley added that the attack seemed to be a "spontaneous attack and that the victims were selected at random."

Read: Man Tries to Flush Baby Down Toilet Before Hours-Long SWAT Standoff: Cops

After interviews with the suspect, his family and witnesses, and after multiple searches, detectives found no evidence of radicalization, he said.

The suspect arrived from Norway to the United Kingdom in 2002.

Helen Edwards, a woman who lives near the attack site, told CBS News, "You live with that threat of terrorism or other crimes in the back of your mind. It wasn't a huge shock I guess."

Watch: Cops: Sarah Palin's Son Track, 26, Is Arrested on Domestic Abuse Charges