Police were searching Monday for a man accused of opening fire on a picnic for a group of employees of a Las Vegas Strip casino-resort, killing a woman and critically injuring a man this weekend in what investigators called workplace violence.

Authorities say Anthony Wrobel walked up to a table at a park and fired a weapon Sunday evening, striking an executive and an employee of The Venetian. Lt. Ray Spencer told reporters that Wrobel also is a Venetian employee who targeted the picnic before he left the park.

A woman in her 50s was killed, and a man, also in his 50s, was being treated for critical wounds. It wasn’t immediately clear which victim was the executive.

Employees of one department at the casino-resort had gathered at the park near McCarran International Airport.

Officer Larry Hadfield, a police spokesman, said a vehicle belonging to Wrobel was found at the airport. Police say the 42-year-old is considered armed and dangerous.

No attorney or publicly listed phone number was immediately available for Wrobel. A motive for the shooting is unclear.

Las Vegas Sands Corp. operates the luxury casino-resort on the Strip. Spokesman Ron Reese said the company is cooperating with authorities and not commenting further because of the ongoing investigation.