The mother took several minutes to open the door, and when she did on Wednesday, she told police that her son never came home the night before.
"He's not here," she repeatedly told the officers.
But he was there, hiding in the basement. The team of Baltimore police sergeants, detectives and officers — all working on a special operation to suppress crime after a spate of shootings in recent weeks — searched the two-story house on the 3500 block of W. Cold Spring Lane and apprehended the suspect.
They served a warrant for a second-degree assault charge stemming from a domestic incident. It was one of hundreds of warrants executed in a matter of days as part of stepped-up efforts to get suspected criminals off the streets.
Between late October and late November, bursts of gunfire across the city alarmed residents, police and the mayor. Eight people were shot in several incidents along a long stretch of Greenmount Avenue. The police commissioner announced that gangs were at war.
Baltimore's homicide count for 2012 reached 200 on Nov. 24, a mark that erases the progress police made last year when the homicide rate fell below 200 for the first time since the 1970s.
Police officials came up with plans to stem the violence. They increased the number of foot patrols citywide, pulling 150 officers from administrative positions to bolster patrol units. They also started the Violence Protection Initiative, police spokesman Anthony Guglielmi said.
The initiative devoted more than 18 district officers to the regional Warrant Apprehension Task Force, made up of law officers from the city and Baltimore County, and the U.S. Marshals Service, for two weeks until Friday.
The increased resources gave the fugitive-hunting detectives and sergeants that make up the task force's nine teams two additional officers each. Baltimore City police also approved additional overtime.
The goal was to arrest suspects with "a nexus of violence" before they could cause more harm, Guglielmi said. Since the initiative began, the task force has made arrests or cleared warrants on more than 300 cases that include charges of assault, burglary and arson, as well as lesser crimes and violations.
No. 224, was the Saturday arrest of Frank James MacArthur, a blogger known as the Baltimore Spectator, who had an open warrant connected to a 2009 weapons charge. He captivated thousands on social media when he holed up in his home and live-streamed discussions with a police negotiator before surrendering without incident.
At least 291 arrests have been made so far. "Essentially that's 291 people who are responsible for wreaking havoc in the community off the streets and delivered to justice," Guglielmi said.
At any given time, the city has more than 50,000 outstanding warrants, task force officers said. Early Wednesday, they fanned out across the city in unmarked cars to addresses they had researched the night before.
The officers carried a stack of warrants with the most dangerous and accessible targets at the top.
At a home near Pimlico just after 5 a.m., they woke up an older woman in a nightgown who led them to a man in the basement wanted for failing to appear in court on a drug charge. They detained him, let him put on his shoes and clothes and walked him out the front door.
"Man, you guys are polite," he said.
But the woman felt differently, peppering the officers with insults and upset by the sudden intrusion.
"You all are fat people," she said.
"Ma'am, I'm big-boned," Sgt. Allen Adkins responded.
Before he got into his car, Adkins remarked that at least he was "fat and free."
Over the course of five hours, the team hit 18 houses.
They found a man sleeping on a couch amid a clutter of shoes, clothes and unopened mail in a home with no power. Lanterns and a kerosene heater sat near him. Police were looking for his uncle, but the man said he hadn't been in the house for months. Then, he added, "There's nobody here that I know of."
The comment heightened the team's suspicion, and the officers checked every room with no results.
At an apartment complex, they encountered a South Asian family who spoke little English; none of them fit the profile of the suspect sought. At another, they called in an interpreter to speak to an El Salvadoran woman, who told officers the man they wanted had left the country. A sergeant called U.S. Immigration and Customs Enforcement to confirm that.
Searching for a woman at a boarding house, they stumbled upon a man who had an open warrant for an assault charge. They arrested him, enraging a woman with him who was carrying a baby.
"He's black! He's black!" she yelled. "You're all messing with him for no reason!"
They led the man away with his hands behind his back in plastic ties as he cursed at the officers.
Confrontations are common. In 1999, while serving a warrant in an attempted-murder case, the suspect split Sgt. Mike Hennlein's police vest with a bullet before shooting himself in the head.
"Been shot at five times," Hennlein said, "only hit once."
Hennlein, a 25-year veteran, said an Ernest Hemingway quote sums up why he hopes to retire on the task force: "There is no hunting like the hunting of man, and those who have hunted armed men long enough and liked it, never care for anything else thereafter."
Warrant officers recently encountered a man who slipped out his window and ran on rowhouse roofs until he jumped, hurt himself and was cornered. They have found people tucked in cupboards, between mattresses and box springs and hidden behind fake walls.
At the house on Coldspring Lane, the suspect's son tipped off officers that he was in the basement. The officers scrambled down a dark stairwell followed by the suspect's mother who continued to claim, "He's not here!"
Hennlein spotted a bed with covers that seemed unfurled in a hurry and felt it. It was warm.
The team searched every corner until Hennlein pulled back a hidden door disguised as a wood-paneled wall. He spied a T-shirt and drew out his Taser.
"Let's do this the easy way," he said. "The red dot you see is a Taser."
The suspect's mother told her son the police are carrying guns.
"I'm coming out," the man said. It was the team's fourth and final arrest Wednesday.