Overall, only about 600 such orders have been issued since the law took effect in 2019, according to the state Office of Court Administration.

“As with any public health law, just passing the law isn’t necessarily going to do anything if the people who know about it aren’t aware of the option,” said Jeffrey W. Swanson, professor at Duke University who works with the law. The school’s gun law center investigates and measures alerts.

Professor Swanson said that if he passed the measure he would call for a “systematic and administrative effort to not only teach people about it but also incorporate it and make it routine”.

According to law enforcement officials and his own online journal, Mr Gendron, who pleaded not guilty to first-degree murder charges, explored the East Side of Buffalo to examine potential sites of the massacre . On Saturday, authorities said, he opened fire outside a Tops supermarket, then entered the store and continued shooting at shoppers and workers before finally surrendering to police.

On Wednesday, Ms. Hochul, a first-term Democrat seeking re-election this year, also urged the Legislature, which is controlled by her fellow Democrats, to pass additional gun safety laws, some of which were already under consideration even before the Buffalo shootings.

Ms Hochul specifically called for legislation that would require the so-called micro-marking of semi-automatic pistols as a way to help law enforcement officers trace casings found at crime scenes back to the weapon that discharged them. Legislation requiring microstamps, which California passed in 2007 despite fierce opposition from gunmakers, has long been discussed in Albany, with bills introduced since at least 2009.

The governor, who is from the Buffalo area, has repeatedly expressed concern about the spread of hate speech online, describing it as “a virus” and condemning “social media platforms where this hate can be spewed” .