Agent Bennett Hirsch is a special agent with the ATF (the Bureau of Alcohol, Tobacco and Firearms). Unknown to his agency and the FBI, Hirsch is a mole in the ATF, and the mastermind in the selling of MG-10, a deadly military-grade government weaponry to a terrorist organization, headed by Jack Kirstein. He is the main antagonist of the episode Surf N Turf in Lethal Weapon.
He is portrayed by Kristoffer Polaha.
Hirsch, being tough and straightforward and all, seems to take the job serious enough as a federal agent, but this is only shows him in covering his deceitful nature in selling illegal firearms on the black market. He even appears to take the job as an agent way too serious than any agent would serious enough, just as he takes the illegal dealing to go well.
Like any crooked official, or any type of criminal for that matter, without thinking twice, he'll stop at nothing to kill anyone who gets in his way and to cover up his crime. This includes even killing witnesses, even before they can even testify before trial.
Hirsch is first seen in Captain Avery's office, where he's introduced to Riggs and Murtaugh. He's well aware that they're investigating a case of a murder at a pool party, which is in connection with the illegal firearms dealing he's investigating, for obvious reasons. There, he offers to lend his expertise to Riggs and Murtaugh when a particularly deadly military-grade weapon, MG-10, is used at a pool party somewhere at a house in the Hollywood Hills, but they decide to work by themselves in the case.
Though unconfirmed by the ATF and the FBI, Hirsch was found out by Riggs in conspiracy of smuggling the government weapons, MG-10, and making the illegal deal to the highest bidder, Jack Kirstein, and kidnapping Natasha, a woman who witnessed the murder at the pool party of Ronald Dawson's residence.
Riggs and Murtaugh go to rescue Natasha at the warehouse where Hirsch's hideout was, where he was settling the deal, and make it look like he was ambushed and then murder Natasha. Riggs gives Murtaugh a signal to shoot the truck filled with firearms and fireworks and other explosives. Just where Hirsch was about to make the getaway, he gets sparked and burnt by the fireworks, which all detonate and blow up the warehouse, with Hirsch killed in the explosion, just as Riggs, Murtaugh and Natasha evacuate the warehouse.