Very Tragic Murder Case In Vegas

Most murders are tragic (criminals who murder criminals, not so tragic) and some are just horrendous and Las Vegas had a horrendous murder case on April 15, 2012.
From the LVRJ: The man, identified by police as 22-year-old Bryan Clay, chased the woman nearly half a mile. He finally caught her near the intersection of Vegas and Tonopah drives and dragged her into the tall weeds off a darkened desert lot.
It was a brief yet brutal encounter: Clay punched, choked and sexually assaulted the woman, according to a police report released Monday.
But the woman fought back, striking Clay in the face with the rock. When police sirens sounded about 2 a.m. that Sunday, Clay snatched the cellphone and fled, leaving behind only a bloodied Cleveland Indians baseball cap.
Sometime in the next hour, Las Vegas police said Clay traveled the half-mile to the Martinez family home at 1016 Robin St. and killed 38-year-old Ignacia "Yadira" Martinez and 10-year-old Karla Martinez with a claw hammer. Police said Karla Martinez was raped, and detectives were still investigating whether Yadira Martinez was also raped, the report said.
The family patriarch, Arturo Martinez, 39, was struck at least three times in the head and his skull was fractured in at least two places, the report said. He has been hospitalized and unable to communicate since the attacks.
The only thing left behind by the apparent attacker was a jacket wrapped in a black T-shirt, discarded in the street and found by a neighbor at 3 a.m. Sunday. The neighbor told police he assumed the jacket belonged to Arturo Martinez and tossed the clothing into the bed of Martinez's pickup truck.
Clay, who police said did not know any of the victims, was arrested early Friday morning after police raided his mother's house.
http://www.lvrj.com/news/arrest-report-slaying-suspect-says-police-should-have-killed-him-149513855.html
As I stated above, this is a horrible and gruesome crime and if this supposed person did this, they ought to let him loose in the general population of prison and let the prisoners have at him.  He would not last 1 hour in prison.
However, there are some questions that are troubling me about this case:
1. When the story first broke, the cops assured everyone that the community was not in danger from a killer and that it appeared the family knew the murderer. The next day or so later, they changed their mind.
2.  Arturo Martinez and his wife are martial art and boxing experts.  How did a man who was so drunk and high able to overpower both of them without a gun or even a knife?
3.  Apparently, the thug defendant just had a scratch on his face.  Wouldn't you think there would be more injuries after fighting these two adults?  And the defendant isn't that big.
4.  How did he get into the house?  Why did the Martinez's let him into the house to begin with?
5. Why the victim's house?
6.  How can he rape a girl and a woman without being hurt by any of the victims, unless he raped them after they were dead?
So, what I do I think happened?  One of three things:
1.  The thug did everything by himself.
2.  He had help from someone close to the family and we have an accomplice
3.  Someone set him up and we still have a murderer on the loose.
I am sure the cops are investigating all of these questions and I hope they are able to answer the questions, otherwise, the defense attorney will have a field day with the investigation.
As far as the Martinez family, yes they were illegal aliens, but they did not deserve any part of this horrific crime.  May the father heal, may the mom and daughter rest in peace and the two survivors young kids  receive all the help they can get.