In Prince George's, a chilling portrait of a skillful serial killer

The man responsible for the slayings of two mothers and their daughters in the Largo area last year is a crafty serial killer who pored through books about forensic science to learn how to clean up his crime scenes and intentionally changed his killing methods to confuse detectives, law enforcement sources close to the investigation said....

For now, at least, he is behind bars on unrelated charges.

"This case before you, I think, is going to be a case study for many law enforcement agencies in the future," Hylton said Tuesday, delivering his first public remarks about the suspect....

"He's a serial killer," Hylton said.

Hylton said the man in custody made efforts to throw detectives off his trail, but he would not say what those efforts were. He also was not specific about the evidence connecting the man to each killing, saying only that it places him at "the scene of the crime."