Last Updated Jun 2, 2016 11:58 PM EDT
LOS ANGELES -- The investigation into a murder-suicide on the UCLA campus took a more sinister turn Thursday when police announced they suspected the shooter earlier killed a woman in Minnesota then drove to Los Angeles to confront a professor he believed had stolen his work.
Detectives also believe that Mainak Sarkar, a 38-year-old former engineering graduate student, intended to kill a second professor Wednesday morning, but could not find him on campus, Los Angeles police Chief Charlie Beck said.
In a search of Sarkar's home in St. Paul, Minnesota, authorities found a "kill list" with at least three names that included professor Bill Klug, the woman found dead in a Minneapolis suburb and a second UCLA professor who was not harmed, Beck said.
The Minnesota victim was identified as Ashley Hasti. She and Sarkar married in 2011, the Hennepin County Clerk's Office confirmed to CBS News. It was unclear whether the couple was still married at the time of the shooting; she was living at a different address from him at time of her death.
CBS Minneapolis station WCCO-TV reported University of Minnesota officials said Hasti enrolled at the university's medical school in 2012 and was still a student there. She also received her undergraduate degree from the school in Asian Language and Literature from the college of liberal arts in 2008.
Sarkar shot and killed Klug, 39, in a UCLA engineering building, leading to a lockdown on the campus with 60,000 or more students and staff members. He then fatally shot himself.
Sarkar was "heavily armed" with two semi-automatic pistols and multiple magazines, Beck said.
"He was certainly prepared to engage multiple victims with the ordnance that he had at his disposal," Beck said.
Police believe the guns were legally purchased. Beck said at least one of the weapons was registered to Sarkar.
Sarkar drove to Los Angeles from Minnesota before he killed Klug. Beck asked for the public's help locating Sarkar's car, a 2003 gray Nissan Sentra with Minnesota license plate 720KTW.
Beck said police believe the vehicle is "likely to contain further evidence of the crime" and will "give a better picture of his motivations and intentions."
He left a note at the scene of the killing that asked anyone who found it to check on a cat at his home in Minnesota, Beck told reporters. It was there that authorities found the "kill list," which led them to a home in a nearby town, where they found Hasti shot dead.
Early indications were that Hasti's death occurred before the murder-suicide at UCLA, police in Brooklyn Park, Minnesota, said in a statement.
Hasti's grandmother told the Minneapolis Star-Tribune the couple "just didn't get along."
Jean Johnson said her granddaughter and Sarkar split about a year after they married, and that Hasti moved back to her hometown of Brooklyn Park, Minnesota. They didn't get a divorce because Hasti couldn't afford one.
"The only enemy she had was him, I guess," Johnson said. "I never thought he would do something like that."
She said Hasti hadn't mentioned any animosity with Sarkar since the two split.
Beck said it appeared mental issues were involved and that Sarkar's dispute with Klug was tied to Sarkar thinking the professor released intellectual property that harmed Sarkar.
A blog post written in March by someone identifying himself as Sarkar said he had personal differences with Klug.
"He cleverly stole all my code and gave it (to) another student," the post says. "He made me really sick."
The blog continues: "Your enemy is your enemy. But your friend can do a lot more harm. Be careful about whom you trust. Stay away from this sick guy."
Beck said UCLA asserts it was all in Sarkar's imagination.
Sarkar is listed on a UCLA website as a member of a computational biomechanics research group run by Klug, a professor of mechanical engineering. Beck said Sarkar graduated from the school in 2013.
In his 2013 dissertation, Sarkar thanked Klug. The dissertation says: "I would like to thank my advisor, Dr. William Klug, for all his help and support. Thank you for being my mentor."
The document thanks several other professors and three friends, with Sarkar saying, "I will always remember all the good time we had together."
The dissertation, approved by Klug and four colleagues, is dedicated to Sarkar's dead mother, Ira Sarkar. It's titled, "Coupled Cardiac Electrophysiology and Contraction using Finite Element."
Classes at the University of California, Los Angeles campus resumed Thursday for most of the school, except for the engineering department, where students and faculty will return Monday.
Klug's colleagues and friends described him as a kind, devoted family man and teacher who didn't appear to have conflicts with anyone.
"Bill was an absolutely wonderful man, just the nicest guy you would ever want to meet," said a collaborator, UCLA professor Alan Garfinkel. The two worked together to build a computer model of the heart, a "50 million variable 'virtual heart' that could be used to test drugs."
The widow of Klug, Mary Elise Klug, released a statement Thursday.
"During this extremely difficult time for our family, we are grateful for the tremendous outpouring of support. This is an indescribable loss. Bill was so much more than my soulmate," she said. "I will miss him every day for the rest of my life. Knowing that so many others share our family's sorrow has provided a measure of comfort."
The university is offering counseling services to students and staff affected by the shooting, CBS Los Angeles reported. Two GoFundMe accounts have been set up to assist with Klug's funeral costs.
Initial reports from the scene set off widespread fears of an attempted mass shooting on campus, bringing a response of hundreds of heavily armed officers. Groups of them stormed into buildings that were locked down and cleared hallways as police helicopters hovered overhead.
Advised by university text alerts to turn off lights and lock doors where they were, many students let friends and family know they were safe in social media posts. Some described frantic evacuation scenes, while others wrote that their doors weren't locking and posted photos of photocopiers and foosball tables they used as barricades.
Those locked down inside classrooms described a nervous calm. Some said they had to rig the doors closed with whatever was at hand.
Umar Rehman, 21, was in a math sciences classroom adjacent to Engineering IV, the building where the shooting took place. The buildings are connected by walkway bridges near the center of the 419-acre campus.
"We kept our eye on the door. We knew that somebody eventually could come," he said, acknowledging his terror.
The door would not lock and those in the room devised a plan to hold it closed using a belt and crowbar, and demand ID from anyone who tried to get in.
Scott Waugh, an executive vice chancellor and provost, said the university would look into concerns about doors that would not lock.
One student who spent hours sheltering in a building did the same thing almost exactly two years ago when he was locked down in a dorm at UC Santa Barbara during a shooting rampage in the surrounding neighborhood that left six students dead and 13 people wounded.
Jeremy Peschard, 21, said it was "eerily similar" but that having been through the feeling of crisis before left him almost numb.
"I just felt a little bit less shocked, a little bit less taken aback by the reality of an active shooter on a college campus," he told The Associated Press in an email. "Because I feel like this is the day and age we're living in, that college campus shootings have genuinely become a normalized threat, almost like a natural disaster, except this type of destruction isn't natural. It's just really sad."