LOS ANGELES • A gunman who shot dead his former college professor in California before taking his own life also murdered his wife as he worked off a "kill list", the authorities and media reports said.

Mainak Sarkar, 38, killed Ms Ashley Hasti in Minnesota and then drove almost 3,200km to Los Angeles, where he shot his former lecturer, Professor William Klug, on Wednesday, according to police and local media.

The shootings prompted a two- hour lockdown of the university.

Officials in Hennepin County, in the mid-western state of Minnesota, said Ms Hasti and Sarkar were married on June 14, 2011. It was unclear if the couple were still married at the time of their deaths.

Prof Klug, 39, a father of two who taught mechanical and aerospace engineering at the University of California, Los Angeles (UCLA), was shot in his office on campus before Sarkar turned the gun on himself, police said.

A note in Sarkar's backpack - in which he asked that someone look after his cat - led police to his home in Minnesota, where a "kill list" was found, Los Angeles police chief Charlie Beck told reporters.

He said Prof Klug was named on the list along with another UCLA professor and the deceased woman, apparently Ms Hasti.

She was found dead of a gunshot wound at her home in the small Minnesota town of Brooklyn Park.

Mr Beck said investigators believe Sarkar killed her earlier in the week before driving to Los Angeles to continue his rampage, armed with two semi-automatic pistols and multiple rounds of ammunition.

"We believe he went there to kill two faculty of UCLA," Mr Beck said, but was able to locate only one.

He said Sarkar was apparently convinced Prof Klug had stolen his computer code and given it to someone else, and seemed bent on revenge.

"That appears to be his motive," Mr Beck said. "We have discussed this with UCLA (which) says there is no truth to it. This was a making of his own imagination."

Mr Beck said UCLA faculty members were aware that Sarkar, who graduated in 2013, harboured anger towards them. "There was some harsh language but certainly nothing that would be considered homicidal," he said, referring to social media postings by Sarkar.

His motive for killing his wife was unclear, Mr Beck added.

AGENCE FRANCE-PRESSE, REUTERS