Mark Kenneth Blank wasn’t bothering anybody. He couldn’t have done so, because his arms were filled with bags of groceries and he was making his way home to his apartment near Waterside Mall in Southwest.

That doesn’t mean others weren’t out to bother him. They were. And oh, how they did.

They beat him to death.

But it took several days before 56-year-old Mark Blank succumbed to his injuries.

I wrote about his October 2008 slaying weeks after it happened [“Watch Where You Walk, Mr. Obama,” op-ed, Nov. 15, 2008]. His death occurred during a period when I seemed to be writing almost weekly about crimes committed by D.C. youth, many of whom had been found guilty and placed in the custody of the city’s Department of Youth Rehabilitation Services (DYRS).

Three people were arrested in connection with Blank’s death. His attackers — 13, 14 and 15 years old — were charged with felony murder.

The Post reported that the 14-year-old, Donte Graves, pleaded guilty to one count of manslaughter and assault with intent to rob, and was committed to DYRS custody.

Once a judge commits a youth to DYRS custody, the court loses control over decisions on the offender’s treatment or length of confinement.

Rehabilitation, as applied by DYRS, is an elastic term.

For the inexcusable, unjustifiable act of killing defenseless Mark Blank and trying to rob him, DYRS placed Graves in secure detention in 2008. In March 2012, DYRS released him into the community.

Today, more than four years after pleading guilty in the death of Mark Blank, Donte Graves is in jail, charged with fatally shooting 22-year-old Tyrone Joyner last month — over a coat.

There is nothing new about this case.

Some young offenders, placed under the city’s supervision for robbing, assaulting and killing, are often let back on the streets, where they rob, assault and kill. According to data DYRS submitted to the D.C. Council’s Human Resources Committee on March 4, 131 youths committed to the agency, ages 17 and younger, were rearrested last year.

Forty-one of them were arrested multiple times.

Among the charges: armed robbery, assault on a police officer, assault with a dangerous weapon, attempted murder, carjacking and carrying a pistol without a license.

In 2011, 198 adults under DYRS care were rearrested.

The agency noted in its report that “An arrest does not constitute an affirmation of involvement in criminal behavior.” When most of the 2011 and 2012 cases were adjudicated, DYRS contended, the majority of the cases were “dismissed or not pursued.”

When DYRS moves young offenders from secure detention to community facilities or group homes, however, they may choose not to stay there. Last year alone, there were 519 reported cases of abscondences or escapes, according to the DYRS data.

Not only did they not stay put, some didn’t stay out of trouble. Seventy-three of the escapees were arrested on new charges.

The pain and suffering all this causes is immeasurable. Mark Kenneth Blank and Tyrone Joyner are two in a long list of victims of youth violence. That some of the attackers are wards of the city makes these victims’ fate all the more galling.

On top of that, the youth corrections system is a money pit that consumes millions of dollars while failing to fully live up to promises or expectations.

To be sure, DYRS can point to reduced rates of recidivism, rearrest and abscondence, as well as declines in deadly violence compared with previous years. No DYRS youth was murdered last year, and only one was charged with murder, down from an average of 11 youths annually charged since 2007, the department’s director, Neil A. Stanley, told the D.C. Council in March 4 testimony.

Under Stanley’s supervision, DYRS has produced programs galore to work with youths in secure detention and community facilities.

And DYRS has poured millions of dollars into D.C. YouthLink, a three-year-old coalition of about 60 community organizations that is supposed to help deliver services to young offenders released back into the community.

In fiscal 2012, DYRS funneled more than $6 million into YouthLink through the city’s Children Youth and Investment Trust Corp.

The corporation is the same agency that former Ward 5 council member Harry Thomas Jr. used to redirect funds for city youth into his own pockets. Thomas is now in jail. And, yes, it’s the same corporation that provided more than $470,000 in city grants to Keely’s District Boxing and Youth Center, whose founders, Keely Thompson Jr. and his wife, Bianca, have been indicted for allegedly fraudulent use of more than $500,000 in city funds. The Thompsons have pleaded not guilty in federal court and are awaiting trial.

“Since its inception, D.C. YouthLink has achieved significant success,” Stanley told the council.

Tell that to Tyrone Joyner’s family and friends.

Read more from Colbert King’s archive.