ROCKY HILL, Conn. — The slaying of four executives at the Connecticut Lottery headquarters was quietly remembered on the 20th anniversary of the shootings Tuesday.

U.S. and state flags outside the Rocky Hill center were lowered to half-staff. No official remembrance was planned, but officials told workers they could mark the anniversary in any way they wanted.

"It's a very sensitive topic," said Kendra Eckhart, interim director of marketing for the lottery. "Our employees don't like to talk about it."

On March 6, 1998, a disgruntled and mentally ill employee, Matthew Beck, gunned down lottery chief Otho Brown and three other officials at the former lottery headquarters in Newington. He killed himself as police arrived.

The other victims included chief financial officer and former New Britain Mayor Linda Mlynarczyk, operations vice president Rick Rubelmann and data processor Michael Logan.

Thirty-one employees who were working that day remain at the agency. The headquarters has a small memorial inside the building that includes photos of the victims, and another outside in a rose garden that includes a plaque.

Democratic Gov. Dannel P. Malloy remembered the victims Tuesday. He noted the shootings led Connecticut to pass the nation's first "red flag" law that allows authorities to temporarily seize guns from people deemed a danger to themselves or others. Only four other states have similar laws.

"It is a shame that only a handful of states have this tool on their statute books," Malloy said in a statement. "I strongly urge all states and the federal government to adopt this critical law enforcement policy — it can save lives.

"Twenty years later, as we look back on the actions that occurred on this tragic day, we must recognize that our nation has not done enough to proactively work to stop the threat of situations such as the one we witnessed here," he said.