A son walks into a nightmare of a scene -- his mother is stabbed to death inside their Houston area apartment, drenched in blood from 48 vicious knife wounds.

At first it's a mystery why anyone would want to so savagely kill this much-loved and admired single mom. But as cops investigated, they uncovered a Texas-size murder plot hatched at a high school by a most unexpected person who was caught hiding in plain sight.

Tabassum Khan was a 43-year-old divorced mother of two who had emigrated from Pakistan to raise her kids on her own in suburban Houston.

"Tabassum Khan was a mother first and foremost. Her whole world revolved around her children," said Harris County Assistant District Attorney Angela Weltin.

The apple of her eye was 17-year-old son Danish Minhas, her youngest child and the only one still living at home.

"She gave him a car, she gave him a credit card, she took care of every one of his needs," said Houston Police Homicide Detective Brian Harris.

But Tabassum was a dedicated hands-on mom who also made Danish earn his privileges, ensuring he attended school and got his school work done. And Danish was living up to his mother's high expectations at his high school, where he was a straight-A senior who was immensely popular with his teachers and fellow students.

"Danish was the class president, Danish was the high school principal student helper," said Det. Harris. "Danish was perceived as the student leader in the school. Danish Minhas was the type of kid that was going to be a winner and was going to be successful in life."

But Danish's world was about to suddenly and tragically come crashing down in November 2009 when he returned home to find his mother lying dead on their living room floor, her head and upper body covered with a blanket. What lies beneath the blanket is like a scene from a horror movie.

A distraught Danish calls 911.

Even veteran homicide detective Brian Harris was shocked when he arrived at the crime scene.

"Tabassum Khan was stabbed repeatedly, over and over and over again, dozens and dozens of times," said Assistant D.A. Angela Weltin. "She had injuries all over her body. The majority were around the neck, the face area, but she also had defensive wounds, showing that she tried to prevent her death."

Her killer had left behind a telltale clue.

"It looked as though we had bloody fingerprints around her ankles as if she was kicking and somebody was holding her legs down while they continued to stab," said Det. Harris.

Investigators initially thought Tabassum may have been murdered during a burglary.

"It was clear, based on evidence, envelopes being moved, the killer was looking for something, which was backed up by the blood splatter and transfer blood on several white envelopes," said Harris.

But cops couldn't find any sign of forced entry at the apartment.

"The door frame was not damaged at all. There was no fresh wood as if somebody pried the door open," said Harris.

That, along with the particularly savage way Tabassum was murdered and the fact that her head was covered by her killer, makes investigators look in another direction.

"That's an indication that perhaps there's a relationship. That the person knew who their victim was," said Harris. "It is also an indication that the person may be shameful."

Now cops try to figure out who that may be.

Who would want Texas mother Tabassum Khan dead? The killer's identity may have been a mystery to this day had he not made one huge mistake. He left a bloody handprint on an apartment door handle.

"That wasn't Tabassum's blood that we were looking at," said Det. Harris.

Cops pore over the forensic evidence and they go back to the 911 call to search for more clues.

Danish, 17, said in the 911 call that he had just returned that morning from Galveston, Texas. That's a clue that tips off homicide detective Brian Harris. Even before being asked where he was that night, Danish had offered an alibi.

"If the killer is actually the one calling 911, they will try to lay out their alibi, and on this 911 tape he mentions he was in Galveston," said Harris.

Harris says Danish then offers more unsolicited information to cover his tracks, about the door being open and unlocked when he came home.

"So either the victim opened up the door, or the door was left open for the killer," said Harris.

Brian Harris says he noticed something else suspicious at the bloody crime scene: Danish's spotless clothing.

"There was no bloodstains. He was completely clean. He looked as if he could be in a magazine modeling for 'Prep University,'" said Harris. "There was something there because you don't find your mom and not go to them, not hold them. There was no staining on his hands.

"Danish Minhas is the type of person that truly believes that he's the smartest person in the room and that he has seen enough crime-scene shows about blood evidence that if he didn't have any on him he certainly wouldn't be a suspect," said Harris.

Investigators also learn that Danish had a fierce argument with his mother just the day before her murder.

"The argument, ironically, was over whether or not she would sign his paperwork to do an internship for the Houston Police Department," said Harris.

"To Danish, it seemed it was all about him wanting to be this man, and that his mother was this obstacle for him to do what it is that he wanted to do with his life," said Assistant D.A. Angela Weltin.

"She wanted me to go into more of a medical professional line and I want to do law and law enforcement," Danish told detectives in a recorded interrogation.

Danish admits he had other arguments with his mother about her being overprotective and too strict in regard to his social life. And Danish says he and his mother also clashed over that the day before she was murdered when he told her he wanted to stay out late that night.

Detectives ask Danish straight out if he might have killed his mother in a rage.

"No. I can't even do that. I can't do that. That's my mother," Danish said in the interrogation.

And Danish offers an alibi, saying he took a girlfriend to the movies in nearby Galveston, dropped her home at 4:30 a.m. and stayed out all night, just like he'd wanted, before returning to his own home nearly four hours later to find his mother stabbed to death.

Detectives don't buy his story, and again they suggest Danish killed his mother, trying to get him to crack. Detectives feel sure Danish is lying.

"This is a kid that his mom would say 'You're not allowed to drive on the freeway and you're not allowed to be out after eight o'clock at night,' and suddenly on a Tuesday during a school night he's going to be allowed to be out all night," said Det. Harris. "It just didn't make any sense."

They accuse Danish of killing his mother, but he sticks with his story.

"I didn't kill my mother. I can't even go there. Why would I kill my mother when she's done so much for me?" Danish says in the interrogation.

That only makes Det. Harris even more certain Danish is their man.

"He was accused of killing his mother, and he continued to take it. An innocent person, they're only going to take just so much of accusations like that," said Harris. "But Danish Minhas, he would have stayed there all night if he was allowed to."

When forensic tests find a bloody handprint on the front door handle of Tabassum Khan's apartment doesn't belong to her son Danish, they still won't believe Danish is innocent.

"He definitely was involved in this crime up to his eyeballs," said Det. Brian Harris.

But they have no evidence to link Danish to his mother's murder -- until one of his classmates is arrested on an unrelated drug charge.

"Nurum Mohamed was a crook, he was a criminal, he was a gang member," said Det. Harris. "He's been involved in robberies and other types of crimes."

But Nur, as he was known, would never have been connected to the killing of Tabassum Khan had the arresting officer not noticed something odd.

"While he was being arrested and walked to the car he kept on shouting to fellow schoolmates, 'Tell Danish, tell Danish. Tell Danish, give me a call. Tell Danish I'm going to jail.' And the officer snapped to that," said Harris.

Harris observes something else a little strange about Nur.

"He was wearing one glove, like Michael Jackson, on his hand, and he takes it off and I see the stitches, and I ask him to explain, 'How'd you get that cut?' And he says he was cutting turkey," said Det. Harris.

But Harris claims Nur really did it while cutting Tabassum Khan, and has his blood is found to match that on the door handle of her apartment.

Confronted with that and other forensic evidence against him, Nur Mohamed confesses that he murdered Tabassum.

But Nur claims Danish paid him to do it. Nur tells detectives the money was to come from robbing Danish's mother.

"He paid me one thousand up front," Nur says in a recorded interrogation.

Nur says Danish drove him to the Houston apartment complex.

"When he dropped me off he opened the trunk, gave me the gloves," said Nur in the interrogation. "There was a knife in the trunk I picked up."

Nur says Danish then goes to the apartment ahead of him.

"He explained to me that 'once I get inside the house' he'll open the door for me," Nur told detectives.

And when Danish returned to his car, Nur says, he goes in to rob Tabassum.

"I grabbed her, I started stabbing her in the stomach, and then she pulled me closer, biting me," Nur says.

He continues stabbing Tabassum, for a total of 48 times, until she's dead. Nur tells detectives he then started looking for the cash that Danish said he would find in a white envelope.

Blood on envelopes would be found to be his, from that cut he got on his hand while stabbing Tabassum.

Detectives had no reason to doubt Nur's confession was the truth.

"Nur was a sociopath," said Det. Harris. "A Ted Bundy kind of person. Very likable guy. But he knew he was caught. And he said once he gave us fingerprints, if we ever came back to him again, he knew he was done, and he said he knew that we had too much evidence on him."

But when confronted with Nur's confession, Danish still denies he had anything to do with his mother's murder, and even denies knowing Nur -- until he's presented with security video showing the two walking and talking together at their high school not long before Khan was stabbed to death.

But Danish blames it all on Nur.

"Trying to claim that Nurum Mohamed was a big bad man who held him at knifepoint, kidnapped him and said 'You're going to help me rob somebody today,' and so Danish led him to his mother and said 'Please don't hurt her,'" said Det. Harris.

But Danish finally comes clean, confessing to cops.

Another shocker in this case: According to investigators, seven other people at his high school knew about the murder and didn't step forward.

"What I find interesting about the people who knew about this is that none of them knew of it from Danish Minhas," said A.D.A. Weltin.

They say the leaker was Danish's hired killer, who told seven school pals what he did, but still managed to keep his dark secret from school officials.

"Everyone who knew about it came from Nur Mohamed, who actually was openly struggling with the act that he did," said Weltin.

Nur Mohamed pleaded guilty and got 40 years. Danish Minhas confessed to being the mastermind behind the murder of his mother and was sentenced to 50 years behind bars.

Now Danish Minhas talks to Crime Watch Daily inside prison walls for his first-ever TV interview.

Danish shuffles through the prison halls in shame, serving 50 years for his role in the murder of his mother.

He tells Crime Watch Daily her death was a crazy teenage plan gone tragically wrong.

"She was never supposed to die," said Danish.

Danish says his classmate Nur Mohammed, who confessed to doing the killing and is serving a sentence of 40 years behind bars, was only supposed to rob Tabassum to make him look like a hero.

"We were supposed to make a staged robbery, basically," said Danish. "I was supposed to come home, 'knight in shining armor, hey, Mom, what happened? I'm here for you -- hey, you know what, this is my time to be your adult son. I'm gonna take care of you.'"

Danish says his hope was that his mother would then treat him like a man instead of a child.

"She doesn't realize I'm a senior in high school," said Danish. "I'm going to college, I'm gonna be a cop, I'm being the man of the house."

Instead, Danish claims he walked into their Houston apartment to find Tabassum dead and drenched in blood from 48 stab wounds.

"At that time, I thought she might still be alive. That's why when I touched her and there was no response, to me that was the end of everything that I knew," said Danish.

Was his 911 call an act, or was that sincere?

"I knew what happened and I knew I was the cause of that. So that was when I was able to really let go of my emotions," said Danish.

He says he hid those emotions when he was questioned by detectives, but then vented them privately.

"And I'm sitting in my car in my driveway and I'm crying, or I'm in the shower crying because I wouldn't cry in front of them," said Danish.

Danish, now 24 years old, says that looking back he sees how foolish he was to hatch such a plot against his own mother.

"I don't think I understood the consequences of, if you do this and things are supposed to go according to plan, Murphy's Law comes into play, and that's what happened," said Danish. "You can't control what the next person might do. That happens."

You didn't understand the consequences of life actions of what you were doing?

"Right, because according to me, since I orchestrated this and no one's supposed to get hurt. Everything's supposed to go down this way and then, I guess, turn of events happen," said Danish.

Do you consider yourself a murderer? Do you consider her blood on your hands?

"Yes. I've wrestled with that a few times. But yes," said Danish.

You feel like you're a better person now?

"To be honest I don't think I was a bad person in the beginning," said Danish. "In the letter of the law, I committed a crime, but I don't have a criminal mindset. I don't believe that."

But Danish admits there have been times when he's thought of killing himself out of guilt over what he did to his mother.

"And I think to myself at times about that and that's when I get depressed. I've contemplated hurting myself," said Danish.

We asked Brian Harris, the homicide detective who put Danish behind bars, for his reaction.

"That doesn't surprise me that Danish would talk about taking his own life, but Danish would never do anything to harm himself, because Danish still believes in his own head that he's the best-looking and smartest guy in that prison," said Det. Harris.

He also scoffed at Danish's claim that he never intended his mother to get hurt.

"Danish is still trying to manipulate you," said Harris. "He's still trying to be the author of his own story. And the story of the murder of his mom. It's already been written. The book is closed on who Danish Minhas is, yet he keeps on trying to reopen it and rewrite his own story, and he just can't get it right."

Danish has plenty of time to work on it. His first chance at parole won't come until 2035.

Is Danish remorseful for what he did? Is he shameful for the hand he played in this?

"Yes, most definitely," said Harris. "I'm not the only one that's actually doing time. My family is doing time with me, but they're essentially robbed of my mom's presence."

Brian Harris offers Danish Minhas some final words of advice: "Until Danish unlocks and grapples with what he did to his own mother, he will forever be in prison. And then at least his soul can be free."