Someone they didn’t know was soliciting donations in Noah’s memory, claiming that they’d send any cards, packages and money collected to his parents and siblings. An official-looking website had been set up, with Noah’s name as the address, even including petitions on gun control.

Noah’s uncle, Alexis Haller, called on law enforcement authorities to seek out “these despicable people.”

“These scammers,” he said, “are taking away from families and the spirits of dead kids.”

It’s a problem as familiar as it is disturbing. Tragedy strikes — be it a natural disaster, a gunman’s rampage or a terrorist attack — and scam artists move in.

It happened after 9/11. It happened after Columbine. It happened after Hurricane Katrina. And after this summer’s movie theater shooting in Aurora, Colo.

Sometimes fraud takes the form of bogus charities asking for donations that never get sent to victims. Natural disasters bring another dimension: Scammers try to get government relief money they’re not eligible for.

“It’s abominable,” said Ken Berger, president and CEO of Charity Navigator, which evaluates the performance of charities. “It’s just the lowest kind of thievery.”

Noah Pozner’s relatives found out about one bogus solicitation when a friend received an email asking for money for the family. Poorly punctuated, it gave details about Noah, his funeral and his family. It directed people to send donations to an address in the Bronx, one that the Pozners had never heard of.

It listed a New York City phone number to text with questions about how to donate. When a reporter texted that number Wednesday, a reply came advising the donation go to the United Way.

The Pozner family had the noahpozner.com website transferred to its ownership. Victoria Haller, Noah’s aunt, emailed the person who had originally registered the name. The person, who went by the name Jason Martin, wrote back that he’d meant “to somehow honor Noah and help promote a safer gun culture. I had no ill intentions I assure you.”

Alexis Haller said the experience “should serve as a warning signal to other victims’ families. We urge people to watch out for these frauds on social media sites.”

Consumer groups, state attorneys general and law enforcement authorities call for caution about unsolicited requests for donations, by phone or email. They tell people to be wary of callers who don’t want to answer questions about their organization, who won’t take “no” for an answer, or who convey what seems to be an unreasonable sense of urgency.

“This is a time of mourning for the people of Newtown and for our entire state,” Connecticut Attorney General George Jepsen said in a statement this week. “Unfortunately, it’s also a time when bad actors may seek to exploit those coping with this tragedy.”

But scam artists know that calamity is fertile ground for profit, watered by the goodwill of strangers who want to help and may not be familiar with the cause or the people they’re sending money to.

After the shootings at Columbine High School in Littleton, Colo., scammers asked for credit card donations for victims’ families. After the 9/11 attacks, the North American Securities Administrators Association warned investors to be wary of Internet postings encouraging them to invest in supposed anti-terrorist technologies.

In 2006, the FBI warned about an email widely circulated after the Sago, W.Va., mine explosion, which claimed to be from a doctor treating one of the survivors and asking for donations to cover medical bills.

“As was learned after the tragic events of 9/11/01, the tsunami disaster, and more recently with Hurricane Katrina, unscrupulous cyber criminals have shown the desire and means to exploit human emotion by attempting to defraud the public when they are perceived to be most vulnerable,” the FBI said at the time.

This fall, the police in Aurora, Colo., accused a local woman of trying to profit off the deadly movie theater rampage by a gunman who killed 12 people. The woman told people that she was the caretaker for a little girl named Kadence, whose mother had died in the shooting. The police said the child was made up. The scam unraveled when a donor got a phone call from what seemed to be a woman imitating a child’s voice.

When the government doled out disaster aid after Hurricane Katrina, scammers asked for money to rebuild houses they never lived in or to pay benefits for relatives who never existed.

The government later set up the National Center for Disaster Fraud to try to root out such scams in the federal relief programs administered after Hurricanes Katrina, Rita and Wilma. It has since expanded its mandate to other disasters.

The cases brought since then by the Justice Department sketch a colorful picture of fraud:

— A woman who filed for small-business disaster benefits after the 2010 Gulf Coast oil spill, even though she’d sold the business before the accident.

— A judge and a commissioner in Texas who, after Hurricane Ike, were accused of awarding debris removal contracts to a company in return for kickbacks. The judge also commandeered a 155-kilowatt generator meant for the county to power his convenience store, according to the government.

— A pastor who submitted inflated claims to a government-funded program that reimbursed groups sheltering Hurricane Katrina evacuees.

Bob Webster, spokesman for the NASAA, knows the sad pattern.

“We know cons try to cash in on headlines, and any who would even think about stooping to capitalize on the tragedy in Newtown are the lowest of the low,” he said.