Mike Ebaugh, center, with the Prince George's County Police Department's robbery unit, talks to America's Best Wings manager Sivakumar Venkataraman, left, about security and recent armed robberies while detectives Brian Layden, back left, and Samuel Tiru stand by as part of an outreach to merchants in Landover Hills, Md. (Evelyn Hockstein/For The Washington Post)

The man in the Cincinnati Reds baseball cap and orange-trimmed shoes had kept police busy.

On the night of Feb. 12, 2015, he robbed a laundromat, a 7-Eleven and a fried chicken shop in Prince George’s County before hitting a second laundromat and another convenience store the same week.

“Where is the money?” he asked one victim with the wave of a gun, according to police charging documents. “If you don’t show me, I’ll kill you.”

Worried the robber would strike again, police set up a surveillance operation and nabbed a man wearing the distinctive shoes and baseball cap during a traffic stop.

With a single arrest, detectives solved five robberies in one night.

The “Cincinnati Reds String” is one in a growing list of cases Prince George’s has solved since redoubling its efforts to drive down robbery rates in 2015. Three years later, police say the strategy is working.

Prince George’s County robbery unit detectives Linden Edwards, left, Terrence Garrett, Samuel Tiru, Mike Ebaugh and Brian Layden, canvass a strip mall in Landover Hills, Md. (Evelyn Hockstein/For The Washington Post)

By targeting serial robbers, leaning on a partnership with the FBI and improving intelligence sharing with neighboring departments, the county solved 74 percent of its commercial robberies in 2017, a 20-percentage-point leap compared with the year before and more than double the success for police departments on average nationwide.

The collaborative effort has led to more than one very swift result.

“We’ve been to the bad guy’s house waiting for him to come home from the robbery,” FBI Supervisory Agent Steve Gordon said. “That has happened three or four times.”

The county’s efforts are part of a broader trend regionally of revamping approaches to tackling robberies.

Prince George’s police and the FBI say quickly solving commercial robberies and putting suspects behind bars is important for preventing heists that hurt people physically and financially.

Sgt. Mike Ebaugh posts a reward sign in a 7-Eleven for information about armed robbers. (Evelyn Hockstein/For The Washington Post)

“It increases the cost of doing business for that business,” said Lt. Sean Carney, commander of the Prince George’s police robbery unit. “They have more trouble getting employees when they’re robbed, and customers won’t want to go to those businesses.”

More important, “a lot of these robberies are a sneeze away from a homicide,” said Gordon, who heads a task force of federal agents and Prince George’s robbery detectives.

Robberies in the county next door to the District dropped 21 percent in 2017 compared with the previous year. Carney and Gordon say much of that success is due to shutting down border-crossing criminals who try to thwart police by relying on their limited ability to straddle jurisdictions or who hope investigators won’t detect crime patterns regionally.

“Before, you would commit a robbery in D.C. and then, the same night, commit a robbery in Prince George’s, and it would be hard for us to make a connection,” Carney said. Officers would “have to call the multiple different stations in D.C. to see what they had that night or if they had anything similar to us. We now share the information through intelligence briefings prepared every day, and it’s our job to monitor not just what happens in Prince George’s, but what happens in the entire metro region.”

In 2015, the county and the FBI created a task force embedding federal agents in the Prince George’s robbery unit. Local detectives were federally deputized, allowing them to conduct investigations in areas outside the county.

The partnership has enabled detectives to spot trends and quickly act on tips and evidence rather than having to wait for help from detectives at other agencies who might not be available until their next shift, Gordon said.

In 2016, the task force arrested three men who were convicted of robbing cellphone stores in Maryland and the District, Carney said. Based on shared lookout details from past robberies, detectives anticipated where the next robbery might occur and set up a surveillance operation that caught the suspects in the act.

In other cases, Gordon said, the task force moved so quickly that officers arrested suspects on the same night of a robbery with the suspects wearing the exact clothes they were spotted in on surveillance videos.

In the District, a similar task force with Metro Transit that launched in 2015 has helped reduce robberies throughout the city. They dropped about 27 percent in 2017 compared with the previous year.

District police joined with Metro Transit and linked in a prosecutor dedicated to robbery cases. Researchers work in the D.C. police command center to quickly connect criminal activity in public spaces to crimes or suspects on the Metro. D.C. police also have a detective in the Metro command center to rapidly get photos and other information out to officers.

D.C. Police Chief Peter Newsham said in December at a news conference touting reduced crime rates that robberies are an important barometer of crime trends and represent the largest category of violent crime in the city.

“Robberies are an extremely difficult crime to close because they happen very quickly,” Newsham said. “It is very difficult for victims of robbery to identify a suspect.”

Montgomery County has partnered with the FBI and Prince George’s County police for the past several years to combat robberies, with one detective federally deputized, Montgomery officials said. They are looking into deputizing more.

The county had 91 commercial robberies in 2016, and about 30 percent were closed, officials said.

“Commercial robbers don’t recognize geographic boundaries,” said Capt. Darren Francke, director of Montgomery’s major crimes division. “This multijurisdictional partnership has really helped put dangerous people in jail.”

Joe Pollini, head of the police science department at the John Jay College of Criminal Justice in New York, said the Prince George’s commercial robbery closure rate is “very good” considering the cases require intense resources to solve.

“Sometimes it’s sheer luck, but most of the time, it’s tenacity and good, bulldog police work that solves the crimes,” said Pollini, who retired from the New York City Police Department after three decades.

In January, Prince George’s announced arrests in two cases in which detectives apprehended suspects or thwarted robberies while they were in the middle of investigating previous cases.

In one of those instances, detectives were collecting surveillance video at a Pizza Hut when two men approached the restaurant preparing to rob it.

In the other, a detective canvassing a 7-Eleven that had been robbed heard on his radio of another heist in progress at a Family Dollar across the street.

With no report of a lookout for a getaway car, Detective Haseeb Munawar instinctively ran to the nearest Metro stop. Munawar showed a wanted poster from the 7-Eleven robbery to the Metro station manager, who said the person on the flier had just run through the gate.

The detective called Metro police to track the suspect, who was waiting on the train platform, while the county detective monitored station security cameras.

As police swarmed, the suspect slid a gun under a bench on the train platform, but it was too late. He was arrested in connection with the Family Dollar and 7-Eleven robberies, and Carney said he has been linked to other cases.

Carney said that while the partnerships with the FBI and agencies around the region have helped close more cases, old-fashioned shoe-leather detective work and good instincts like Munawar’s make a big difference.

“We do proactive stuff,” Carney said. “We don’t go out and interview people and go back to our desk. We go out and look for the bad guys.”

Peter Hermann and Dan Morse contributed to this report.