Police are continuing their search for the person responsible for a series of deadly shootings, but this is not the first time Valley residents have had to be on high alert.

RELATED: Full coverage of Phoenix serial shootings

Catch up on two previous serial killer cases -- the Baseline Killer and the Serial Shooters -- that rocked local neighborhoods.

The Baseline Killer

It's hard to believe that it has been more than 10 years since 'Baseline Killer' Mark Goudeau terrorized residents along the Baseline corridor.

The city conducted numerous community meetings, plastered the city with sketches of his description, offered $100,000 for information, and even had the 'Guardian Angels' patrolling the streets of Phoenix searching for him.

More than 70 charges were filed against Goudeau, including nine killings, 15 sexual assaults and various other robberies and kidnappings that occurred between the fall of 2005 and June 2006.

All but one of the victims were women going about their normal business, waiting for buses, washing their cars, or coming and going from work.

He usually attacked his victims at night wearing disguises, including a wig of dreadlocks and a fisherman's hat.

Most of the attacks occurred in Phoenix along Baseline Road. Goudeau lived about three miles from Baseline.

Although Goudeau and his family always maintained his innocence, prosecutors linked his DNA to several of the victims. Some of the victims' property was also found in his home.

In November 2011, he was sentenced to death and is being held on death row.

The Serial Shooters

From 2005 to 2006, the Valley was also plagued with another round of random nighttime shootings and killings. Roommates Dale Hausner and Samuel Dieteman together committed 80 crimes, including six counts of first-degree murder, attempted murder, aggravated assault, and cruelty to animals.

In addition to killing six people, the pair also wounded 18 others, shot several dogs, and a horse. They also set fire to a couple of Walmart stores, causing millions of dollars in damage. In all, the state filed 88 charges against Hausner.

The shootings mostly occurred overnight, the victims were pedestrians and bicyclists, and were shot from Hausner's car, usually with a shotgun or a .22 caliber rifle.

It was an anonymous call to Silent Witness from a person saying they heard their friend Samuel Dieteman talking about the shootings and his involvement in them.

Police identified Dieteman from surveillance video at the Walmart arsons. Police tracked the two and conducted wiretaps as they gathered evidence against them. When police searched their apartment, they found weapons, news clippings and videos of the shootings. Police later realized that Hausner and Dieterman also returned to the crime scenes as onlookers.

Dieteman turned on Hausner and testified against him at trial in exchange for a life sentence.

Dale Hausner committed suicide in prison on June 19, 2013 while he was sitting on death row.