The gunman who killed a professor at the University of California Los Angeles (UCLA) had a 'kill list', police say, which led them to find a woman dead in Minnesota.
Mainak Sarkar is said to have taken his own life after shooting Bill Klug at the university campus on Wednesday.
Investigators found a note at the scene naming a second UCLA professor, and leading to the shooter's home.
There investigators discovered a document marked 'kill list'.
It named the two UCLA professors and a young woman, who was later found dead at her home.
LA police chief Charlie Beck said Sarkar, a former doctoral student who left UCLA's engineering school in 2013, had driven from Minnesota to Los Angeles within the last couple of days to kill Klug before killing himself.
Sarkar may have believed that Klug had stolen his intellectual property in the form of a computer code, said Beck, but there was no truth to such claims.
Investigators believe Sarkar also intended to kill the second professor, but he was not on campus at the time of the shooting.
They are searching for the grey Nissan Sentra they believe Sarkar drove from Minnesota.
The gunman was "heavily armed" with two semi-automatic pistols, including one used in the shooting, as well as several magazines and loose rounds of ammunition, Beck said. At least one of the guns was registered to Sarkar, he added.
Sarkar left a note at the UCLA murder scene requesting someone "check on my cat", prompting investigators to search his Minnesota home where the "kill list" was discovered.
A blog post apparently written by Sarkar called Klug a "sick guy" and said the two had had personal differences, according to the AP news agency.
"Your enemy is your enemy. But your friend can do a lot more harm. Be careful about whom you trust," the blog reads.
The UCLA campus remained under lockdown for hours on Wednesday as a massive police operation took place.
Colleagues of Klug's said he was a married father of two and described him as a kind, gentle person.
The Los Angeles Times reported that he was trying to develop a computer-generated virtual heart.
Staff and students barricaded themselves inside buildings during the lockdown on the massive UCLA campus.
About 43,000 students are enrolled there.