A suspect is taken into custody on a violation of a protective order warrant during a warrant sweep earlier this month in Landover, Md. (Matt McClain/The Washington Post)

In the middle of the night, a sheriff’s deputy thumped on the door as officers surrounded the Upper Marlboro house of a woman suspected of stealing from a family member. Lights flicked on, the door opened, and within minutes, they led the suspect to a squad car in her pajamas.

“Another one bites the dust,” one deputy said as he headed back to his car, ready for the next arrest.

It was the first catch of the night one recent Tuesday for a team of Prince George’s County sheriff’s deputies searching for people accused of crimes. The sweep sent 10 teams of deputies and other county and state law enforcement officers into the dark streets from 10 p.m. to 6 a.m.

“You want to get these guys off of the street before they commit another crime,” said Lt. Randall Cooper, a commander in the warrant and fugitive squad of the Prince George’s Sheriff’s Office.

The night was part of the county’s ongoing effort to reduce its backlog of more than 42,000 outstanding warrants and reduce crime. The latest push — aimed at catching the most violent suspects — came over the past four months. County and state law enforcement agencies arrested about 600 people and served about 1,000 warrants in late-night sweeps funded by a $125,000 state grant.

Officers have picked up a46-year-old former Riverdale man accused of stabbing his wife in 2010. Deputies have also arrested a 21-year-old man in Landover in a carjacking case. And they captured a 38-year-old rape suspect who has also been accused of assault, child sex abuse, sodomy and incest.

Prince George’s Sheriff Melvin High said targeting the newest warrants — more than 2,000 come in each month — and those involving the most serious crimes is an important strategy to prevent crime.

“People who have freshly committed a crime are more likely to commit another crime,” High said.

The Sheriff’s Office came under scrutiny in 2010 and 2011 when county residents learned that deputies failed to serve warrants or arrest suspects who were later accused of killing others or committing additional crimes. The Sheriff’s Office has reduced the number of outstanding warrants by 21 percent in the past three years, down from nearly 54,000 when High took office in 2010.

Some of those closed warrants have resulted from administrative purges, such as eliminating dead people from the rolls or killing outdated warrants. But officials say much that decrease also comes from the recent sweeps and increased manpower on the warrant and fugitive squad. Three years ago, there were only about 10 deputies dedicated to the unit. Now there are 26 on the squad.

But going after the worst criminals is inherently dangerous work.

During the county’s most recent warrant sweep, a man wielding knives barricaded himself in his house, Cooper said. The man almost stabbed a deputy, and the Sheriff’s Office version of a SWAT team was called. Officers evacuated neighboring homes, broke in and dragged the man — who had five outstanding assault warrants — out of the house about 5 a.m.

That incident was the most extreme of the night, in which officers knocked on more than 200 doors and arrested 65 people.

All the sweeps take place in the dark of night or early morning.

“It’s kind of when folks are stumbling in,” Cooper said. “It gives us the element of surprise, knocking on doors at 2 a.m.”

But even an unannounced visit from sheriff’s deputies isn’t always unexpected. In his years on the warrant squad, Cooper has seen people bury themselves under piles of dirty laundry, crawl inside clothes dryers and build false walls to avoid being caught. One person — fully prepared for a nighttime visit from deputies — had cut a hole his a bed, hiding between the mattress and the box spring when officers came knocking.

Prince George’s Police Chief Mark Magaw said the county’s focus on closing warrants for suspected violent criminals is one major reason crime has decreased this year. Violent crime is down 15 percent compared with this time last year, and overall crime is down 12 percent.

“These numbers are more than just statistics,” Magaw said. “What these numbers mean is so far this year we’ve had 3,000 less victims this year than we did last year.”

With one of the busiest county court systems in the state, High said the next challenge will be to find ways to keep up with new warrants now that the grant-funded program has ended.

“We have everybody out there every day from the Sheriff’s Office serving warrants and bringing people back for trial,” High said. That work will continue, but next is: ‘Where do we find our additional resources that can continue to boost us?’ ”