RANCHO CORDOVA (CBS13) – The brother-in-law of the Rancho Cordova woman killed along with her two toddler children Tuesday has been arrested and identified as the only suspect in their deaths.

Grigoriy Bukhantsov, 19, was detained Wednesday at 2 a.m. at a Denny’s in Rocklin after police found a white minivan belonging to the family of the slain mother and children parked outside, according to Sacramento Sheriff Department spokesman Sgt. Jason Ramos.

Grigoriy Bukhantsov

Bukhantsov is the woman’s brother-in-law.

Police found the 19-year-old sleeping inside a booth in the restaurant with a plate of chicken fried steak with gravy. He was then taken in for an interview.

“Based on that interview as well as what we have learned throughout the investigation since yesterday afternoon, we have arrested him for the murders of all three victims,” Ramos said. “We believe he is the only person responsible for this. We’re not looking for any outstanding suspects at this time.”

The Sacramento County Coroner’s Office on Wednesday identified the victims as Alina Bukhantsov, 23, daughter Emmanuela, 3, and son Avenir, 2.

According to Ramos, the father came home to the house in the 10100 block of De Soto Way about 3:30 p.m. and saw the bodies inside. He ran to a neighbor’s house and they called 911.

Alina Bukhantsov and her husband (source: David Bukhantsov)

The 2-year-old boy and 3-year-old girl were killed “very violently” along with their mother, Ramos said. A crying 6-month-old baby boy was also located in the back of the home unharmed in a crib.

Ramos said the victims all sustained “sharp force trauma.” He didn’t say if the murder weapon was recovered.

Emmanuela and Avenir Bukhantsov (source: David Bukhantsov)

“This is somebody who confronted a family inside their homes and took their lives very violently,” he said.

Ramos had to pull himself away from an on-camera interview Monday to compose himself.

“We’re all human so it impacts all of us significantly,” he said. “We’re looking into everything. We have a mom and two kids dead.”

Alina’s family issued a statement Tuesday night: “We’ll greatly miss her and the children. She was a lovely woman of heart, one of a kind, an awesome mom for the babies. We still can’t believe they’re gone.”

CBS13 learned Alina was a Sunday school teacher at a local Slavic church and had recently graduated from Sacramento State.

A motive for the killings has not been released but Ramos said Grigoriy Bukhantosov had a strained relationship with the family. He was booked into the Sacramento County Jail and is being held on the psychiatric ward.

“There have been some suggestions that something bad was brewing for some time,” Ramos said.

Bukhantosov was arrested in 2011 for allegedly burglarizing a home in Carmichael, which was caught on surveillance video.

(The Associated Press contributed to this story.)