The gunman responsible for a deadly shooting in January at a mall in Columbia, Md., had an obsession with the Columbine massacre, authorities said on Wednesday.

Police say that Darion Marcus Aguilar, 19, intended for his attack to be similar to that of the Columbine massacre, reports The Washington Post.

They discovered that Aguilar had been researching information on the Internet about the 1999 shooting at Columbine High School. He even timed his attack to start at 11:14 a.m., which was the same time the two Columbine shooters walked into the school.

Aguilar entered the mall with a Mossberg 500 series pump-action shotgun and crude explosives. He shot and killed two people; 21-year-old Brianna Benlolo and 25-year-old Tyler Johnson, both workers at a store called Zumiez. He injured five others, before killing himself. Although he had about 54 rounds with him, he fired nine in total.

According to The Baltimore Sun, authorities believe that Aguilar began his research in January 2013. Besides looking up mass shootings such as the Columbine Massacre, he also looked up websites on mental illness and suicide help.

He kept a journal as well, documenting his thoughts from that year, which included feelings of sadness and depression. He also stated at one point that he was ready to die and kill others.

Aguilar had no connection to either victim. Police concluded that it was an act of randomness.

“Nobody saw this coming,” Howard County Police Chief, William H. McMahon said.

Image courtesy of Wikimedia Commons