The Marine

In Iraq, John Triton (John Cena) of the United States Marine Corps is closing in on an al-Qaeda hideout. There are only 3 hostages. Those 3 hostages are actually Marines. Disregarding direct orders to wait for reinforcement, Triton attacks the extremists and rescues his Comrades. The next morning, his colonel informs Triton that he is being honorably discharged for disobeying direct orders.
Home from Iraq, Triton finds it hard to settle back in to normal life. He is fired from his job as a security guard for using excessive force on an employee's ex-boyfriend and his bodyguards. Triton should not have thrown the guy through a window. It is still hilarious that the window broke. Triton's wife Kate (Kelly Carlson) decides the two need a vacation to help Triton adjust to his new life. Meanwhile, criminal Rome (Robert Patrick) robs a jewelry store with his gang: girlfriend Angela (Abigail Bianca), Morgan (Anthony Ray Parker), Vescera (Damon Gibson), and Bennett (Manu Bennett). Rome is in collusion with an anonymous partner, with whom he is planning on sharing the profits from the diamonds. On the run, the gang stops at a gas station where Triton and Kate have stopped. When two policemen arrive to buy gas, Morgan shoots and kills one of the officers, causing Rome to shoot the other officer while Angela kills the gas station attendant. When Triton reacts to Kate being kidnapped, Bennett knocks him out. Triton regains consciousness and gives chase in the policemen's car. The chase leads to a lake, where Triton falls out of the patrol car and into the lake, seemingly to his death.
Rome and his gang walk through a swamp to avoid the police. Kate tries to escape several times. Triton emerges from the lake to find Detective Van Buren, who is pursuing the gang. Van Buren denies Triton permission to pursue the gang, but Triton heads into the swamp anyway. After an altercation between Morgan and Vescera, Rome decides to kill Vescera. Rome gets a call from his anonymous partner, and Rome tells him that he intends to cut the partner out of the deal.
The gang arrives at a lodge and decide to rest there for the time being. Meanwhile, Triton is kidnapped by two fugitives who believe he is a police officer looking for them. He subdues them and tracks the gang to the lodge. He kills Morgan and Bennett then drags the bodies under the lodge, where he again meets Detective Van Buren.
Kate rushes out of the lodge, but Angela attacks and recaptures her. Meanwhile, Triton enters the lodge and finds himself face-to-face with Rome and his gun. Van Buren enters the room but points his gun at Triton, revealing himself to be the anonymous partner. Rome opens fire on Triton, who uses Van Buren as a human shield, killing him. Rome makes his escape and joins up with Angela and Kate before firing at a gasoline tank and blowing up the lodge. Triton makes a narrow escape, having been blown into the swamp.
Rome escapes in Van Buren's car, but abandons it due to a police tracking device. Angela seduces then kills a truck driver for his truck. Triton is arrested by a marine patrol officer, but steals the officer's vessel after handcuffing him. He races to the marina that is Rome's destination, jumping on Rome's truck, throwing Angela into the windshield of an oncoming bus, killing her and spilling the diamonds. Rome scrapes Triton off the truck by driving into the side of a building, careening through a warehouse, then leaps out just before the truck crashes into a lake. Triton then stumbles out, leaving Rome in the fiery warehouse, then rescues Kate, who is drowning in the truck. A badly-burned Rome returns and tries to choke Triton with a chain. Triton kills Rome by breaking his neck with the chain. The film ends with Triton and Kate kissing as the police arrive.

Question: who is used as a human shield?
Answer: Van Buren