As the city’s first line of defense, the New Orleans Police Department is inexorably familiar with violence and tragedy. Over the weekend, detectives investigated the city’s 103rd murder of the year.

But the past few weeks have been particularly trying for the NOPD, as the agency has coped with one case after another hitting excruciatingly close to home.

Officers have buried a colleague gunned down in the line of duty — the lowest point for any law enforcement organization — while two members of the department have lost immediate family members to a resurgent wave of killings.

Then the NOPD suffered another blow early Sunday when Officer Vernell Brown, a 17-year veteran of the force, was struck by a car and severely injured while investigating a vehicle fire on the Pontchartrain Expressway.

Even as officers gathered Monday at Interim LSU Hospital, where Brown remained in grave condition in a coma, the department was well represented at the funeral the same day of Milan Arriola, the 20-year-old daughter of Officer Imani Ruffins who was fatally shot July 3 in Gentilly.

The string of misfortunes, to say the least, has knocked the collective wind out of the NOPD’s ranks. But Police Superintendent Michael Harrison said he has been heartened by the dedication and strength officers have shown in the face of adversity.

“It’s been a very hard couple of weeks,” Harrison said in an interview Monday. “But I’m finding that our department is a resilient department, just like our city is a resilient city. It makes me proud to see that our men and women are not just laying down.”

Police develop a professional carapace over the course of their careers that helps them move from one calamity to the next. But the toll of a crime is greatly compounded when it affects a brother in blue. That sentiment is shared by the broader law enforcement community, not to mention the families and friends of those who serve.

“My heart really goes out to the department,” said state Sen. J.P. Morrell, D-New Orleans, who has two brothers on the force. “As someone who’s related to an officer, there’s never been a time when I’ve been more fearful for them on the beat than I am right now.”

The NOPD is still trying to heal from the June 20 killing of Daryle Holloway, the officer fatally shot as he drove 33-year-old Travis Boys to Central Lockup. The pain caused by Holloway’s death was compounded by the recent arrest of Wardell Johnson, the officer accused of hampering the investigation into the shooting by hiding — and disposing of — evidence. Meanwhile, the son of Officer Jeardine Daniels-Sparks has been investigated for potentially aiding Boys in his daylong flight from the authorities after the shooting.

The dog days of summer also have proved exceptionally violent so far, taxing the department’s overwhelmed Homicide Section. On the same day as Holloway’s killing, Raymond Ambrose Jr., 78, the father of a New Orleans police officer, killed his ailing wife in New Orleans East before turning the gun on himself in an apparent murder-suicide, police said.

“Add on top of that the murder of Officer Ruffin’s daughter and the injury to Officer Brown, and people are left with the question: ‘What’s next?’ ” said Donovan Livaccari, an attorney for the Fraternal Order of Police.

While Harrison said the department has not experienced a decline in morale, Livaccari said the enthusiasm among the ranks has yet to rebound from the wide-ranging U.S. Department of Justice investigation of the NOPD and the resulting federal consent decree signed by Mayor Mitch Landrieu in 2013.

The department’s lack of manpower affects “practically every aspect of an officer’s job,” he said.

“These tragedies could have a unifying effect both within the NOPD and with the community,” he added. “We will have to wait and see what the leadership is capable of. For the time being, there are many people who are sad, disgusted and/or disenchanted.”

Harrison said that officers — even those who have not shown signs of trauma — have been offered counseling and the opportunity to speak with a chaplain and police psychologist. The chief noted that two recruits witnessed Brown being struck by a Ford Mustang after stepping out of his NOPD vehicle on the shoulder of the expressway.

“They have chosen not to let it defeat them,” said Col. Mike Edmonson, the State Police superintendent, whose troopers have worked closely with the NOPD and maintained an increased presence in the city in recent months. “They’re using each one of these events to just get stronger. They’re not looking backwards.”

Even as officers have faced repeated challenges, some have found comfort in an outpouring of public support. After Holloway’s death, thousands of residents gathered in his family’s 7th Ward block for an evening memorial service. Hundreds of motorcyclists from New Orleans-area clubs paraded down the street — so many, according to 6th District Cmdr. Ronnie Stevens, that police stopped counting at 500 bikes.

“I had never seen anything like that in my 24 years as a police officer. I’ve seen it for other beloved people, but never for citizens doing it for us. They loved Daryle,” Harrison said at a June 24 department commanders’ meeting. “It was something to really behold.”

Staff writer Matt Sledge contributed to this report. Follow Jim Mustian on Twitter, @JimMustian.