His tape-recorded confession to killing a child gave police and prosecutors everything they thought they needed to send Melvin Lorenzo Jones to prison, probably for the rest of his life.
What the confession didn't reveal was a reason for the brutal crime. "It started raining," he told his interrogators. "I just snapped, lost it, grabbed him around his neck" and stabbed 11-year-old Irvin Harris more than a dozen times last year as the boy fought for his life.
Police and prosecutors got what they hoped for. Yesterday, Jones pleaded guilty to first-degree murder in Baltimore Circuit Court. His sentence of 50 years probably means the 53-year-old will die in prison.
But some of the mysteries remain, especially why Jones, who had been convicted of molesting children but never before been accused of this kind of violence, killed a boy that he had befriended.
He remained silent at the hearing yesterday, offering neither explanation nor apology. His voluble confession after his arrest last summer - which was made available to The Sun this week - while an admission of guilt, also failed to reveal any understanding of the why.
"We started walking, and I don't know what happened after that," Jones told police just minutes into the tape recording. "I just started stabbing him. I stabbed him to death."
Confessions often arm prosecutors with evidence that helps win convictions. But those confessions sometimes don't illuminate larger questions about the motivations and triggers underlying violent, detestable acts.
That is certainly true in the case of Jones. In his 24-minute confession, he immediately and casually admits to the killing. But between bouts of caginess, he also demonstrates not the least insight into why he murdered Irvin.
"I did not have no intention or inkling at all to do it," Jones matter-of-factly told the pair of homicide detectives in the police interview room.
"It might sound weird, but we were fine. And then as it started raining, I just snapped, lost it, grabbed him around his neck."
Detective Robert F. Cherry Jr., in his thick Boston accent, pushed Jones.
"What made you snap? ... What happened? What took place right then?"
"I don't know," Jones replied.
Cherry said in an interview yesterday that "all humans want to know" why someone has committed a crime.
He said he and Sgt. Kelvin Sewell wanted to know why Jones killed Irvin so that, if the case went to trial, the prosecutor could offer a motive to jurors who might not want to convict without one.
In every criminal case, a clear motive is useful to jurors and judges who are "trying to understand the full picture of what happened," said John Carroll Byrnes, who retired in 2002 after 20 years on the Baltimore Circuit Court bench.
It can help a jury choose between first- and second-degree murder and a judge choose an appropriate prison sentence, he said.
For a defendant, articulating a motive "might produce some sympathy" that a crime "wasn't some random, evil act, but something motivated by an emotional driver."
Cherry said he wasn't satisfied by Jones' confession because it "left a lot of unanswered questions," particularly about motive. But it was a good confession, Cherry said, because it left no room for doubt that Jones committed the crime.
In a steady voice, Jones told the detectives that on the afternoon of July 28, 2006, he and Irvin took a walk in the Northeast Baltimore neighborhood where the child lived with his family.
The two had known each other for several years, Jones said, but had not seen each other all week. So they were catching up as they walked along the streets and through shopping mall parking lots and, finally, through the woods behind a church.
Then, Jones said, when it started to rain, "The next thing I know, I just grabbed him by his neck, and I threw him over the tree trunk. And he was fighting."
Irvin himself - like the detectives - tried to understand why Jones would hurt him. The boy had recently taken an interest in a neighborhood girl.
"He kept saying, `Melvin, I love you. Why are you doing this? What are you doing. What are you doing?' He said, `Is it my girlfriend?' And I never answered ...
"He just kept going on, `I don't want to die, I'm not ready to die.'"
Jones said he never spoke a word as he pulled a buck knife out of his pocket and stabbed Irvin over and over.
According to the autopsy report, Irvin was stabbed 14 times in the chest; eight slash marks on his hands and right arm show that he tried to fight off his attacker.
When Cherry asked Jones whether he was jealous of the new friendship between Irvin and the girl, he replied, "To be honest, yes. ... It was getting to the point where he wasn't spending time with me."