On Sunday night, "I said, 'Please come home. It's your birthday tomorrow. I want to give you a hug and a kiss,’ " Abreu recalled.
"He told me, 'Mommy, I love you. I want to hang out with my friends.'"
On Monday morning, a Palm Beach Gardens officer and two detectives came to Abreu’s place of work to tell her that her son was dead.
"My son didn't deserve this," she said.
Now Abreu has a gift, unopened.
‘An amazing soul’
"My son was an amazing soul," she said. "He had the biggest personality wherever he went. He brightened up a room. He always told jokes and made people laugh. We always told him he should be a comedian."
Abreu said she came from Colombia and lived briefly in Missouri, where Jovanni Sierra was born. She said the Watson P. Duncan Middle School student played soccer in a youth league and aspired to be a marine biologist. She said Jovanni Sierra has an 8-year-old sister, Isabella. Abreu said her husband, Oliver Abreu, a construction worker, "loved him as his own son."
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Abreu's Facebook page shows a photograph of her son with the words, "Rest in Peace." One person posted in Spanish, "There are no words."
Jovanni Sierra's Facebook page has only a few postings. The most recent was on March 20, 2017, and contained a baby picture. It had one comment, from a woman who wrote, "I had so much fun with you when you were a baby. You have turned out to be such a good boy. Love you Jovanni."
‘God has taken an angel’
Abreu said services for her son are pending but are tentatively set for the end of this week at the Christ Fellowship church in Palm Beach Gardens.
On Tuesday, Abreu's former employer set up a money-raising page to pay for Jovanni's funeral. By Tuesday evening, it had raised $400 of its $15,000 goal.
“They're an amazing family," Maria Pishos, a former co-worker of Karen, said Tuesday.
She said Abreu worked for about a year and a half as a receptionist at Jonathan T's Hair Styling, in Palm Beach Gardens, which Pishos owns with her husband.
Pishos said she called Abreu on Monday and Abreu told her it was true; that her son had died. She said she traded several texts with Abreu on Tuesday.
"God has taken an angel, but you know, he’s in a better place and doesn't have to suffer any more," Abreu said Tuesday.
"My last words to my son were, 'I love you and have fun,'" she sobbed. "I never imagined that was the last time I would see him."