The beginning of season 21 finds the series back where it began, with the Broward Sheriff’s Office. First up, the officers chase down a hit and run driver. A long run ends with a ramming, followed by an investigation of the vehicle which uncovers a machete. Next, a known drug area finds a man on a bicycle who tries to flee. A search reveals cocaine on a man who is on probation. Lastly, officers are responding to a call about a suspicious vehicle near a business. The driver begins to flee as officers arrive. An investigation uncovers a bleary-eyed man behind the wheel who claims to be sleeping, yet a bag of white powder gives the officers another idea.

Palm Beach County Sheriff's witness a speeding car in a drug infested area. Having stopped them in a pursuit, the driver angrily exits his vehicle to ask why he was stopped. He jumps back in his car and speeds off beginning a new chase in which a passenger bails out. The female is the drivers boyfriend which is only discovered after a long inquiry. She reveals he has a vial of crack inside the car. Next, a Spokane Police officer is called to a possible domestic call on the street. Looking up and down the road the officers discover a man standing under a tree in which a female is up in the tree. They find out that the woman often climbs the tree when upset with family problems. Then, a Rialto Police officer spots a drug transaction taking place. The men claim they are construction workers headed to purchase supplies, but a bag of crack on the floor has the officer in doubt.

The Palm Beach County Sheriff Officers vice unit have set up a sting operation, using a pair of undercover officers in a pickup truck as buyers. The first seller takes the officers straight to a drug house to sell their crack. The suspect is quickly arrested after lighting up his crack on the way home. The second deal happens when a young man offers to sell the officers crack and asks them to join him for a smoke behind a gas station. Then, an officer in Las Vegas is summoned when a restaurant claims a man refused to pay his $400 bill. He is trapped by the manager and a waiter. The suspect first claims his friend paid the tab and then changes his story and says he paid the bill himself. The man is arrested when it's discovered he has warrants and now can add the unpaid bill to the charges. Lastly, an officer in Palm Beach has stopped a car for a tint violation. Lowering his window, a cloud of marijuana smoke billows out from the car and a small amount of crack and cocaine is also discovered.

A pair of Broward County Sheriff's pat down a couple of guys who are hanging out in front of a store. One man becomes agitated and pulls away as drug paraphernalia is discovered on him and are forced to subdue him with a taser. Then, as a North Las Vegas Police officer arrives for a call concerning a fight between two men, the suspects flee in opposite directions. One officer misses with a taser shot, but the suspect gives up anyways. The other officer has also subdued him man. Lastly, a Rancho Cucamonga Police deputy chases a car which looses control. The passenger explains that the driver is his boyfriend and they were arguing inside the car about infidelities, which was the cause of the erratic driving.

A North Las Vegas Police officer is sent to a home in which they have visited before for domestic disturbance. The crowd outside the home inform the officer that a man is beating up his wife. The man is tackled and taken into custody, admitting the fight was caused by rent issues. Then, a Broward County Sheriff's detective takes part in stopping a vehicle believed to have been involved in a drug deal. The woman inside the car has a gun and half a pound of marijuana in her purse. Lastly, a Pomona Police officer rolls up to a home where several windows have been smashed. The victim states that the female passenger from his vehicle smashed the windows in his truck with a pipe. She claims to have had racial slurs thrown at her.

An informant has the Broward Sheriff’s deputies tracking down a male suspect believed to be selling drugs. Rancho Cucamonga Police officers are sent to a bank robbery and the suspects have unknowingly left behind enough clues to locate them. A call regarding domestic abuse sends the San Diego County Sheriff's officers to a familiar home.

A group of suspect run off when a pair of Broward County Sheriff Deputies spot a bunch of people gambling. Next, a San Diego County Sheriff Deputy stops a vehicle which was involved in a burglary in the previous week. Then, a pair of Rancho Cucamonga Police Deputies assist on a traffic stop. A routine stop becomes a full arrest when the information for the vehicle doesn't match that given by the driver.

A Rancho Cucamonga Police Officer responds to a call in which a man is shooting his gun off in his yard. Next, a North Las Vegas Police Officer is sent to a domestic call for a lover's quarrel. Lastly, a San Diego County Sheriff’s Deputy responds to a 'code cover' call to help detain an armed subject.

A North Las Vegas Police Officer is called to assist when another officer captures a suspect wanted for a hit and run which occurred earlier in the day. Next, a Rancho Cucamonga Police Officer responds to a domestic call in which the intoxicated husband has fled the residence on foot. Lastly, the North Las Vegas Police Department is needed when a domestic call is received.

A routine vehicle stop by a Broward County Sheriff Officer ends up a bit more complicated after the driver dumps some evidence. Next, a North Las Vegas Police Officer responds to a domestic call which turns out to involve a love triangle. Lastly, a San Diego County Sheriff Officer stops a vehicle which had expired tags and receives a bunch of lies as excuses.

A Rancho Cucamonga Police Officer responds to a shoplifting call at the mall, and wind up finding a suspicious substance on the suspect. Then, a North Las Vegas Police Officer is called to an apartment where shots are being fired and discover overwhelming but questionable evidence at the scene. Lastly, a Broward County Sheriff pulls over a car which is showing erratic driving by the operator.

A pair of Broward County Sheriff Officer's are summoned to a residence to take down an ecstasy dealer. Then, a Pomona Police Officer is dispatched to an incomplete 911 call which ends up involving a domestic violence situation. Later, a North Las Vegas Police Officer is called in to a disturbance at a bus stop which involves a married couple.

An officer in Minneapolis sets up the groundwork for a prostitution sting, and in the process pick up a number of working women. Then, a County Sheriff's Officer spots two men and women milling around at a truck stop. Lastly, a Snohomish County Sheriff's Officer is called in to a disturbance at a pub.

Cops from the Fondren Division Tactical Unit at Houston's PD chase a guy suspected of murder. Then some cops from North Las Vegas PD bust a guy for domestic battery and finally some Californian cops from San Bernardino bust a guy for X possession.

A Harris County Sheriff's deputy chases down a flatbed truck which is overloaded with golf carts. Then, a North Las Vegas Police officer spots a mini van driving around a parking lot with it's lights shut down. Lastly, a Rialto Police officer pulls up after seeing a collision between an SUV and a semi truck.

A Rialto Police Officer chases down a man who is using his wife's car as a battering ram in knocking a car off the road. Then, a Harris County Sheriff's Officer is dispatched to check a car which is believed to be containing a rifle aboard. Lastly, the Rancho Cucamonga Police Deputies check out a man and his parked car in a neighborhood which is not his.

Deputies in Harris County, Texas, respond to a domestic-violence call that escalates into a high-speed pursuit; detectives in Rancho Cucamonga, Cal., deal with a physical altercation between neighbors; and Las Vegas police detain shoplifters.

A suspicious-person call in Harris County, Texas, turns into a case of narcotics possession; a motorcyclist is taken in on a DUI charge in Rancho Cucamonga, Cal.; sheriffs in San Diego County, Cal., investigate a grocery-store theft.

Broward County, Fla., sheriffs go undercover for a drug sting; Harris County, Texas, deputies break up a physical altercation between a father and son; and Rancho Cucamonga, Cal., police stop a drunken man from riding a bicycle.

Officers in Sacramento apprehend a suspect driving a stolen vehicle---but he claims he didn't know it was stolen. Also: Minneapolis police respond to a suspicious-person call and find someone lurking in an alley; and deputies in Rancho Cucamonga, Cal., arrest a woman who admits to smoking pot but lies about her true identity.

Cleveland, OH Division of Police - Officer Kevin Coleman and Officer Bruce Garner roll to assist in the pursuit of a vehicle reported stolen. Hillsborough County, FL Sheriff's Office - Deputy Brad Hickory spots two men parked in a truck around midnight. Sacramento, CA Police Department - Officer Michael Harbison stops a suspicious pedestrian and questions the man.

Officers in Sacramento pursue a carjacker, which progresses from a car chase to a foot pursuit. A Hillsborough County Sheriff's deputy is called in for a theft in progress. Lastly, Houston Police officers go on a drug sweep.

An officer in Sacramento, CA. stops a driver who hands his passenger his illegal substances. Next, a King County, WA police helicopter is in search for a suspect who has threatened to kill his girlfriend. Lastly, a Florida officer questions a suspect who was caught siphoning gas from a car and was also snorting cocaine.

Texas deputies assist in a felony arrest warrant. Next, Pomona, CA. officers answer a call for a domestic-disturbance when a daughter tells her mother about her Las Vegas wedding. Lastly, police officers in Minnesota break up a fight between two women.

A King County Sheriff's deputy responds to a call for a disturbance at a local eatery. Then, a pair of Minneapolis Police Officers are called for a man assaults a woman and must use a Taser to bring him down. Next, a North Las Vegas Police Officer is called in when a man beats up a woman as she tried to retrieve her mother's possessions.