A man that authorities are calling a serial killer was charged with murder and is believed to be the person behind the five-day Los Angeles shooting rampage.

Alexander Hernandez's shotgun and pistol grip were connected to shootings in the San Fernando Valley by the Los Angeles Police Department, according to LA Times reports.

The timing, weapons used and the description of Hernandez's vehicle also helped lead detectives to the suspect, reports The Associated Press.

"Nothing makes a homicide investigator's heart beat faster than realizing he has a serial killer. And that is what this man was," sheriff's Chief of Detectives Bill McSweeney told LA Times. "This man is and was a serial killer.... I don't think we will ever have an adequate explanation for these terrible murders. How do you explain anything like this?"

Three people and two dogs were killed in the rampage and several others were injured, according to police reports.

Prosecutors are planning to hold Hernandez without bail and his charges may include a death penalty if found guilty, says AP.

Hernandez had a scheduled arrangement Tuesday, but he missed it after refusing to leave his jail cell, according to LA Times.