"There are very few places on Earth where I find any bit of peace, and this is one place that is peaceful to me," Kiernan said. "It's one of the only places where I know where my son is."
The 18-year-old Marine from Rochester died in February while serving in California after doctors diagnosed him with what they thought was the flu, but ended up being flesh-eating bacteria.
"By the time they found out, it was too late," Kiernan said.
Since his burial, Kiernan has spent countless hours at the Massachusetts National Cemetery in Bourne where her son's grave is covered in coins.
"I come here and I talk, and I talk to him," Kiernan said.
It's a military tradition for visitors to leave a penny if they knew the fallen. A nickel left at the grave means they were in boot camp together, a dime means they served together and a quarter means they were together when he or she died.
"It's just a more generalized sign of respect," Kiernan said.
However, over the last few weeks, the coins have gone missing, and at one point, they all disappeared. On a few other occasions, only the special coins have vanished.
"Another Gold Star mom whose son is buried here too came to visit Beck," Kiernan said. "She left a very special silver half dollar with him and I just knew, it's Saturday, special coin, and it's going to go missing – and within 24 hours, it was gone."
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While cemeteries often collect coins to maintain the grounds or pay for burials, Kiernan says the cemetery director told her the groundskeepers may have blown away the coins while mowing the grass.
Yet Kiernan says that, based on how often the grass has been cut and the frequency of the coins’ disappearance, she's confident someone has been stealing them.
"It just makes me sick to think that someone thinks it's OK to take from him," Kiernan said.
She says she wants her pain to be a lesson for kids to never disrespect the dead while also hoping that whoever is responsible for it has a change of heart.
"I don't understand what's broken in them that they just see a coin and take it from an 18-year-old Marine who gave everything," Kiernan said.
State police say they have been stepping up their patrols at the cemetery and groundskeepers are keeping an eye out.
In a statement to WFXT, State police spokesperson Dave Procopio said a trooper assigned to patrol Joint Base Cape Cod, which includes the cemetery, has been monitoring the area. Other patrols have also been made aware of the situation and check on the area as much as possible.