VALPARAISO, Ind. (CBS) — The BB gun shooter eluded police for more than three months, shooting car windows and moving vehicles in Lake and Porter, Ind., counties. But one observant eyewitness and a Wal-Mart surveillance tape gave police a crucial break in the case, leading to the arrest Wednesday evening of 38-year-old Valparaiso resident Dennis Ditterline.

On May 9, the Valparaiso Police Department received a call about someone in a minivan shooting a BB gun in broad daylight in the Valparaiso Wal-Mart parking lot.

Valparaiso resident Robert Perich, who lives in his van, was waking up when he saw a Ford Explorer SUV pull behind his minivan. Almost immediately, he heard a loud bang and ducked for cover. Perich then tried to glimpse the SUV that the shots allegedly came from. Perich remembered the SUV’s license plate number and tan and blue exterior, which he relayed to police.

A Porter County Sheriff’s Department detective used Wal-Mart surveillance video to identify Ditterline. On tape, Ditterline enters the store and is later spotted checking out at a cash register. He used a credit card to make his purchase, and police matched purchase records to identify him and get his address.

After the break in the case, police sporadically surveyed Ditterline’s residence and began round-the-clock surveillance Wednesday morning. Police followed Ditterline when he left his home Wednesday evening and observed Ditterline shooting a BB gun at a target. After the shooting, police arrested him at a traffic stop at 1005 S. County Line Road at 7:19 p.m.

Ditterline admitted to 75 Porter County BB gun shootings: three moving vehicles and 22 parked cars or other targets in Valparaiso, and 12 moving vehicles and 38 parked cars or targets in Porter County. He also admitted to one shooting in the Winfield area.

He faces several counts of Class A misdemeanor criminal mischief for all nonmoving vehicle shootings and Class D felony criminal recklessness charges for all moving-vehicle shootings. Police were in the process of filing charges at 11:30 a.m. Wednesday but said it was obvious they arrested the right person.

“He had working knowledge of what had taken place,” Valparaiso Police Department Detective Sgt. Jeff Balon said.

Ditterline admitted to shootings as far back as Feb. 12, but BB gun shootings began in the area in October 2010. Ditterline remains a suspect for the other BB gun shootings in the ongoing investigation.

Unsolved incidents include four car shootings in Morgan and Pleasant townships on Dec. 24 and Dec. 30, two of which were occupied moving vehicles.

Police are also still investigating two moving school bus BB gun shootings Jan. 4 and 5 in Crown Point along 109th Avenue. Crown Point school buses continued to be targeted, and two were shot at again on Jan. 28.

Crown Point rerouted the buses to avoid 109th Avenue and Lake County Police helicopters patrolled the area. While shootings took place in Crown Point and Winfield, most shootings were in southern Porter County.

Police took the BB shootings seriously, with Porter County, Lake County and a Crown Point businessman offering $1,000 rewards for information.

Ditterline is married with children, unemployed and had no criminal history.

“He said he was frustrated with life,” Balon said. “Problems at home, money problems, stuff like that.”

Police said Ditterline didn’t target anyone. Ditterline allegedly took almost any opportunity he was in his car alone to shoot, including during errands such as cigarette purchases.

Both Balon and Jones emphasized the importance of collaborating with Merrillville and Lake County Police, saying the crack in the case is a testament to old-fashioned police work. Jones said police will still pursue the other BB gun shootings, and Jones recognized it’s “possible others are out there.”

“People are going to get hurt if this stuff keeps happening,” Jones said.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2010. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)