LOS ANGELES A man was arrested Monday on suspicion of killing his mother after pushing her out a second-story window in Van Nuys, police said.

CBS Los Angeles reports it happened at about 3 a.m. in the 7400 block of Hazeltine Avenue at their apartment building the two had shared for about 10 years.

Police said Carlota Vargas, 70, and her son were arguing when he pushed her.

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After she landed on the pavement, Fernando Vargas, 40, then jumped from the window and beat his mother while she lay on the ground, Los Angeles police Officer Norma Eisenman said.

Friends were shocked and devastated after learning about Vargas’ violent death.

Erika Lehmann was beside herself when she learned the bad news. “God bless her. She’s up there with him,” she wept.

“She’s nice. She’s happy. She’s friendly,” said Solange Lehmann, adding that Fernando was not like the boy she knew growing up.

Former neighbor, Sheila Tucker, said Vargas was devoted to her son, always cooking for him and doing everything he needed.

“Everything is my son, my son. Every word came out of her mouth was my son,” Tucker recalled.

The suspect was treated for an ankle injury and was booked on suspicion of murder.

Police said he was being tested for drugs.